java.util
Class Arrays
java.lang.Object
|
+--java.util.Arrays
- public class Arrays
- extends Object
This class contains various methods for manipulating arrays (such as
sorting and searching). It also contains a static factory that allows
arrays to be viewed as lists.
The documentation for the sorting and searching methods contained in this
class includes briefs description of the implementations. Such
descriptions should be regarded as implementation notes, rather than
parts of the specification. Implementors should feel free to
substitute other algorithms, so long as the specification itself is adhered
to. (For example, the algorithm used by sort(Object[]) does not
have to be a mergesort, but it does have to be stable.)
- Since:
- JDK1.2
- See Also:
Comparable
,
Comparator
Method Summary |
static List |
asList(Object[] a)
Returns a fixed-size list backed by the specified array. |
static int |
binarySearch(byte[] a,
byte key)
Searches the specified array of bytes for the specified value using the
binary search algorithm. |
static int |
binarySearch(char[] a,
char key)
Searches the specified array of chars for the specified value using the
binary search algorithm. |
static int |
binarySearch(double[] a,
double key)
Searches the specified array of doubles for the specified value using
the binary search algorithm. |
static int |
binarySearch(float[] a,
float key)
Searches the specified array of floats for the specified value using
the binary search algorithm. |
static int |
binarySearch(int[] a,
int key)
Searches the specified array of ints for the specified value using the
binary search algorithm. |
static int |
binarySearch(long[] a,
long key)
Searches the specified array of longs for the specified value using the
binary search algorithm. |
static int |
binarySearch(Object[] a,
Object key)
Searches the specified array for the specified object using the binary
search algorithm. |
static int |
binarySearch(Object[] a,
Object key,
Comparator c)
Searches the specified array for the specified object using the binary
search algorithm. |
static int |
binarySearch(short[] a,
short key)
Searches the specified array of shorts for the specified value using
the binary search algorithm. |
static boolean |
equals(boolean[] a,
boolean[] a2)
Returns true if the two specified arrays of equals are
equal to one another. |
static boolean |
equals(byte[] a,
byte[] a2)
Returns true if the two specified arrays of bytes are
equal to one another. |
static boolean |
equals(char[] a,
char[] a2)
Returns true if the two specified arrays of chars are
equal to one another. |
static boolean |
equals(double[] a,
double[] a2)
Returns true if the two specified arrays of doubles are
equal to one another. |
static boolean |
equals(float[] a,
float[] a2)
Returns true if the two specified arrays of floats are
equal to one another. |
static boolean |
equals(int[] a,
int[] a2)
Returns true if the two specified arrays of ints are
equal to one another. |
static boolean |
equals(long[] a,
long[] a2)
Returns true if the two specified arrays of longs are
equal to one another. |
static boolean |
equals(Object[] a,
Object[] a2)
Returns true if the two specified arrays of Objects are
equal to one another. |
static boolean |
equals(short[] a,
short[] a2)
Returns true if the two specified arrays of shorts are
equal to one another. |
static void |
fill(boolean[] a,
boolean val)
Assigns the specified boolean value to each element of the specified
array of booleans. |
static void |
fill(boolean[] a,
int fromIndex,
int toIndex,
boolean val)
Assigns the specified boolean value to each element of the specified
range of the specified array of booleans. |
static void |
fill(byte[] a,
byte val)
Assigns the specified byte value to each element of the specified array
of bytes. |
static void |
fill(byte[] a,
int fromIndex,
int toIndex,
byte val)
Assigns the specified byte value to each element of the specified
range of the specified array of bytes. |
static void |
fill(char[] a,
char val)
Assigns the specified char value to each element of the specified array
of chars. |
static void |
fill(char[] a,
int fromIndex,
int toIndex,
char val)
Assigns the specified char value to each element of the specified
range of the specified array of chars. |
static void |
fill(double[] a,
double val)
Assigns the specified double value to each element of the specified
array of doubles. |
static void |
fill(double[] a,
int fromIndex,
int toIndex,
double val)
Assigns the specified double value to each element of the specified
range of the specified array of doubles. |
static void |
fill(float[] a,
float val)
Assigns the specified float value to each element of the specified array
of floats. |
static void |
fill(float[] a,
int fromIndex,
int toIndex,
float val)
Assigns the specified float value to each element of the specified
range of the specified array of floats. |
static void |
fill(int[] a,
int val)
Assigns the specified int value to each element of the specified array
of ints. |
static void |
fill(int[] a,
int fromIndex,
int toIndex,
int val)
Assigns the specified int value to each element of the specified
range of the specified array of ints. |
static void |
fill(long[] a,
int fromIndex,
int toIndex,
long val)
Assigns the specified long value to each element of the specified
range of the specified array of longs. |
static void |
fill(long[] a,
long val)
Assigns the specified long value to each element of the specified array
of longs. |
static void |
fill(Object[] a,
int fromIndex,
int toIndex,
Object val)
Assigns the specified Object reference to each element of the specified
range of the specified array of Objects. |
static void |
fill(Object[] a,
Object val)
Assigns the specified Object reference to each element of the specified
array of Objects. |
static void |
fill(short[] a,
int fromIndex,
int toIndex,
short val)
Assigns the specified short value to each element of the specified
range of the specified array of shorts. |
static void |
fill(short[] a,
short val)
Assigns the specified short value to each element of the specified array
of shorts. |
static void |
sort(byte[] a)
Sorts the specified array of bytes into ascending numerical order. |
static void |
sort(byte[] a,
int fromIndex,
int toIndex)
Sorts the specified range of the specified array of bytes into
ascending numerical order. |
static void |
sort(char[] a)
Sorts the specified array of chars into ascending numerical order. |
static void |
sort(char[] a,
int fromIndex,
int toIndex)
Sorts the specified range of the specified array of chars into
ascending numerical order. |
static void |
sort(double[] a)
Sorts the specified array of doubles into ascending numerical order. |
static void |
sort(double[] a,
int fromIndex,
int toIndex)
Sorts the specified range of the specified array of doubles into
ascending numerical order. |
static void |
sort(float[] a)
Sorts the specified array of floats into ascending numerical order. |
static void |
sort(float[] a,
int fromIndex,
int toIndex)
Sorts the specified range of the specified array of floats into
ascending numerical order. |
static void |
sort(int[] a)
Sorts the specified array of ints into ascending numerical order. |
static void |
sort(int[] a,
int fromIndex,
int toIndex)
Sorts the specified range of the specified array of ints into
ascending numerical order. |
static void |
sort(long[] a)
Sorts the specified array of longs into ascending numerical order. |
static void |
sort(long[] a,
int fromIndex,
int toIndex)
Sorts the specified range of the specified array of longs into
ascending numerical order. |
static void |
sort(Object[] a)
Sorts the specified array of objects into ascending order, according to
the natural ordering of its elements. |
static void |
sort(Object[] a,
Comparator c)
Sorts the specified array of objects according to the order induced by
the specified comparator. |
static void |
sort(Object[] a,
int fromIndex,
int toIndex)
Sorts the specified range of the specified array of objects into
ascending order, according to the natural ordering of its
elements. |
static void |
sort(Object[] a,
int fromIndex,
int toIndex,
Comparator c)
Sorts the specified range of the specified array of objects according
to the order induced by the specified comparator. |
static void |
sort(short[] a)
Sorts the specified array of shorts into ascending numerical order. |
static void |
sort(short[] a,
int fromIndex,
int toIndex)
Sorts the specified range of the specified array of shorts into
ascending numerical order. |
Methods inherited from class java.lang.Object |
clone,
equals,
finalize,
getClass,
hashCode,
notify,
notifyAll,
toString,
wait,
wait,
wait |
sort
public static void sort(long[] a)
- Sorts the specified array of longs into ascending numerical order.
The sorting algorithm is a tuned quicksort, adapted from Jon
L. Bentley and M. Douglas McIlroy's "Engineering a Sort Function",
Software-Practice and Experience, Vol. 23(11) P. 1249-1265 (November
1993). This algorithm offers n*log(n) performance on many data sets
that cause other quicksorts to degrade to quadratic performance.
- Parameters:
a
- the array to be sorted.
sort
public static void sort(long[] a,
int fromIndex,
int toIndex)
- Sorts the specified range of the specified array of longs into
ascending numerical order. The sorting algorithm is a tuned quicksort,
adapted from Jon L. Bentley and M. Douglas McIlroy's "Engineering a
Sort Function", Software-Practice and Experience, Vol. 23(11)
P. 1249-1265 (November 1993). This algorithm offers n*log(n)
performance on many data sets that cause other quicksorts to degrade to
quadratic performance.
- Parameters:
a
- the array to be sorted.fromIndex
- the index of the first element (inclusive) to be
sorted.toIndex
- the index of the last element (exclusive) to be sorted.- Throws:
- IllegalArgumentException - if fromIndex > toIndex
- ArrayIndexOutOfBoundsException - if fromIndex < 0 or
toIndex > a.length
sort
public static void sort(int[] a)
- Sorts the specified array of ints into ascending numerical order.
The sorting algorithm is a tuned quicksort, adapted from Jon
L. Bentley and M. Douglas McIlroy's "Engineering a Sort Function",
Software-Practice and Experience, Vol. 23(11) P. 1249-1265 (November
1993). This algorithm offers n*log(n) performance on many data sets
that cause other quicksorts to degrade to quadratic performance.
- Parameters:
a
- the array to be sorted.
sort
public static void sort(int[] a,
int fromIndex,
int toIndex)
- Sorts the specified range of the specified array of ints into
ascending numerical order. The sorting algorithm is a tuned quicksort,
adapted from Jon L. Bentley and M. Douglas McIlroy's "Engineering a
Sort Function", Software-Practice and Experience, Vol. 23(11)
P. 1249-1265 (November 1993). This algorithm offers n*log(n)
performance on many data sets that cause other quicksorts to degrade to
quadratic performance.
- Parameters:
a
- the array to be sorted.fromIndex
- the index of the first element (inclusive) to be
sorted.toIndex
- the index of the last element (exclusive) to be sorted.- Throws:
- IllegalArgumentException - if fromIndex > toIndex
- ArrayIndexOutOfBoundsException - if fromIndex < 0 or
toIndex > a.length
sort
public static void sort(short[] a)
- Sorts the specified array of shorts into ascending numerical order.
The sorting algorithm is a tuned quicksort, adapted from Jon
L. Bentley and M. Douglas McIlroy's "Engineering a Sort Function",
Software-Practice and Experience, Vol. 23(11) P. 1249-1265 (November
1993). This algorithm offers n*log(n) performance on many data sets
that cause other quicksorts to degrade to quadratic performance.
- Parameters:
a
- the array to be sorted.
sort
public static void sort(short[] a,
int fromIndex,
int toIndex)
- Sorts the specified range of the specified array of shorts into
ascending numerical order. The sorting algorithm is a tuned quicksort,
adapted from Jon L. Bentley and M. Douglas McIlroy's "Engineering a
Sort Function", Software-Practice and Experience, Vol. 23(11)
P. 1249-1265 (November 1993). This algorithm offers n*log(n)
performance on many data sets that cause other quicksorts to degrade to
quadratic performance.
- Parameters:
a
- the array to be sorted.fromIndex
- the index of the first element (inclusive) to be
sorted.toIndex
- the index of the last element (exclusive) to be sorted.- Throws:
- IllegalArgumentException - if fromIndex > toIndex
- ArrayIndexOutOfBoundsException - if fromIndex < 0 or
toIndex > a.length
sort
public static void sort(char[] a)
- Sorts the specified array of chars into ascending numerical order.
The sorting algorithm is a tuned quicksort, adapted from Jon
L. Bentley and M. Douglas McIlroy's "Engineering a Sort Function",
Software-Practice and Experience, Vol. 23(11) P. 1249-1265 (November
1993). This algorithm offers n*log(n) performance on many data sets
that cause other quicksorts to degrade to quadratic performance.
- Parameters:
a
- the array to be sorted.
sort
public static void sort(char[] a,
int fromIndex,
int toIndex)
- Sorts the specified range of the specified array of chars into
ascending numerical order. The sorting algorithm is a tuned quicksort,
adapted from Jon L. Bentley and M. Douglas McIlroy's "Engineering a
Sort Function", Software-Practice and Experience, Vol. 23(11)
P. 1249-1265 (November 1993). This algorithm offers n*log(n)
performance on many data sets that cause other quicksorts to degrade to
quadratic performance.
- Parameters:
a
- the array to be sorted.fromIndex
- the index of the first element (inclusive) to be
sorted.toIndex
- the index of the last element (exclusive) to be sorted.- Throws:
- IllegalArgumentException - if fromIndex > toIndex
- ArrayIndexOutOfBoundsException - if fromIndex < 0 or
toIndex > a.length
sort
public static void sort(byte[] a)
- Sorts the specified array of bytes into ascending numerical order.
The sorting algorithm is a tuned quicksort, adapted from Jon
L. Bentley and M. Douglas McIlroy's "Engineering a Sort Function",
Software-Practice and Experience, Vol. 23(11) P. 1249-1265 (November
1993). This algorithm offers n*log(n) performance on many data sets
that cause other quicksorts to degrade to quadratic performance.
- Parameters:
a
- the array to be sorted.
sort
public static void sort(byte[] a,
int fromIndex,
int toIndex)
- Sorts the specified range of the specified array of bytes into
ascending numerical order. The sorting algorithm is a tuned quicksort,
adapted from Jon L. Bentley and M. Douglas McIlroy's "Engineering a
Sort Function", Software-Practice and Experience, Vol. 23(11)
P. 1249-1265 (November 1993). This algorithm offers n*log(n)
performance on many data sets that cause other quicksorts to degrade to
quadratic performance.
- Parameters:
a
- the array to be sorted.fromIndex
- the index of the first element (inclusive) to be
sorted.toIndex
- the index of the last element (exclusive) to be sorted.- Throws:
- IllegalArgumentException - if fromIndex > toIndex
- ArrayIndexOutOfBoundsException - if fromIndex < 0 or
toIndex > a.length
sort
public static void sort(double[] a)
- Sorts the specified array of doubles into ascending numerical order.
The sorting algorithm is a tuned quicksort, adapted from Jon
L. Bentley and M. Douglas McIlroy's "Engineering a Sort Function",
Software-Practice and Experience, Vol. 23(11) P. 1249-1265 (November
1993). This algorithm offers n*log(n) performance on many data sets
that cause other quicksorts to degrade to quadratic performance.
- Parameters:
a
- the array to be sorted.
sort
public static void sort(double[] a,
int fromIndex,
int toIndex)
- Sorts the specified range of the specified array of doubles into
ascending numerical order. The sorting algorithm is a tuned quicksort,
adapted from Jon L. Bentley and M. Douglas McIlroy's "Engineering a
Sort Function", Software-Practice and Experience, Vol. 23(11)
P. 1249-1265 (November 1993). This algorithm offers n*log(n)
performance on many data sets that cause other quicksorts to degrade to
quadratic performance.
- Parameters:
a
- the array to be sorted.fromIndex
- the index of the first element (inclusive) to be
sorted.toIndex
- the index of the last element (exclusive) to be sorted.- Throws:
- IllegalArgumentException - if fromIndex > toIndex
- ArrayIndexOutOfBoundsException - if fromIndex < 0 or
toIndex > a.length
sort
public static void sort(float[] a)
- Sorts the specified array of floats into ascending numerical order.
The sorting algorithm is a tuned quicksort, adapted from Jon
L. Bentley and M. Douglas McIlroy's "Engineering a Sort Function",
Software-Practice and Experience, Vol. 23(11) P. 1249-1265 (November
1993). This algorithm offers n*log(n) performance on many data sets
that cause other quicksorts to degrade to quadratic performance.
- Parameters:
a
- the array to be sorted.
sort
public static void sort(float[] a,
int fromIndex,
int toIndex)
- Sorts the specified range of the specified array of floats into
ascending numerical order. The sorting algorithm is a tuned quicksort,
adapted from Jon L. Bentley and M. Douglas McIlroy's "Engineering a
Sort Function", Software-Practice and Experience, Vol. 23(11)
P. 1249-1265 (November 1993). This algorithm offers n*log(n)
performance on many data sets that cause other quicksorts to degrade to
quadratic performance.
- Parameters:
a
- the array to be sorted.fromIndex
- the index of the first element (inclusive) to be
sorted.toIndex
- the index of the last element (exclusive) to be sorted.- Throws:
- IllegalArgumentException - if fromIndex > toIndex
- ArrayIndexOutOfBoundsException - if fromIndex < 0 or
toIndex > a.length
sort
public static void sort(Object[] a)
- Sorts the specified array of objects into ascending order, according to
the natural ordering of its elements. All elements in the array
must implement the Comparable interface. Furthermore, all
elements in the array must be mutually comparable (that is,
e1.compareTo(e2) must not throw a ClassCastException
for any elements e1 and e2 in the array).
This sort is guaranteed to be stable: equal elements will
not be reordered as a result of the sort.
The sorting algorithm is a modified mergesort (in which the merge is
omitted if the highest element in the low sublist is less than the
lowest element in the high sublist). This algorithm offers guaranteed
n*log(n) performance, and can approach linear performance on nearly
sorted lists.
- Parameters:
a
- the array to be sorted.- Throws:
- ClassCastException - if the array contains elements that are not
mutually comparable (for example, strings and integers).
- See Also:
Comparable
sort
public static void sort(Object[] a,
int fromIndex,
int toIndex)
- Sorts the specified range of the specified array of objects into
ascending order, according to the natural ordering of its
elements. All elements in this range must implement the
Comparable interface. Furthermore, all elements in this range
must be mutually comparable (that is, e1.compareTo(e2)
must not throw a ClassCastException for any elements
e1 and e2 in the array).
This sort is guaranteed to be stable: equal elements will
not be reordered as a result of the sort.
The sorting algorithm is a modified mergesort (in which the merge is
omitted if the highest element in the low sublist is less than the
lowest element in the high sublist). This algorithm offers guaranteed
n*log(n) performance, and can approach linear performance on nearly
sorted lists.
- Parameters:
a
- the array to be sorted.fromIndex
- the index of the first element (inclusive) to be
sorted.toIndex
- the index of the last element (exclusive) to be sorted.- Throws:
- IllegalArgumentException - if fromIndex > toIndex
- ArrayIndexOutOfBoundsException - if fromIndex < 0 or
toIndex > a.length
- ClassCastException - if the array contains elements that are
not mutually comparable (for example, strings and
integers).
- See Also:
Comparable
sort
public static void sort(Object[] a,
Comparator c)
- Sorts the specified array of objects according to the order induced by
the specified comparator. All elements in the array must be
mutually comparable by the specified comparator (that is,
c.compare(e1, e2) must not throw a ClassCastException
for any elements e1 and e2 in the array).
This sort is guaranteed to be stable: equal elements will
not be reordered as a result of the sort.
The sorting algorithm is a modified mergesort (in which the merge is
omitted if the highest element in the low sublist is less than the
lowest element in the high sublist). This algorithm offers guaranteed
n*log(n) performance, and can approach linear performance on nearly
sorted lists.
- Parameters:
a
- the array to be sorted.c
- the comparator to determine the order of the array.- Throws:
- ClassCastException - if the array contains elements that are
not mutually comparable using the specified comparator.
- See Also:
Comparator
sort
public static void sort(Object[] a,
int fromIndex,
int toIndex,
Comparator c)
- Sorts the specified range of the specified array of objects according
to the order induced by the specified comparator. All elements in the
range must be mutually comparable by the specified comparator
(that is, c.compare(e1, e2) must not throw a
ClassCastException for any elements e1 and
e2 in the range).
This sort is guaranteed to be stable: equal elements will
not be reordered as a result of the sort.
The sorting algorithm is a modified mergesort (in which the merge is
omitted if the highest element in the low sublist is less than the
lowest element in the high sublist). This algorithm offers guaranteed
n*log(n) performance, and can approach linear performance on nearly
sorted lists.
- Parameters:
a
- the array to be sorted.fromIndex
- the index of the first element (inclusive) to be
sorted.toIndex
- the index of the last element (exclusive) to be sorted.c
- the comparator to determine the order of the array.- Throws:
- ClassCastException - if the array contains elements that are not
mutually comparable using the specified comparator.
- IllegalArgumentException - if fromIndex > toIndex
- ArrayIndexOutOfBoundsException - if fromIndex < 0 or
toIndex > a.length
- See Also:
Comparator
binarySearch
public static int binarySearch(long[] a,
long key)
- Searches the specified array of longs for the specified value using the
binary search algorithm. The array must be sorted (as
by the sort method, above) prior to making this call. If it
is not sorted, the results are undefined. If the array contains
multiple elements with the specified value, there is no guarantee which
one will be found.
- Parameters:
a
- the array to be searched.key
- the value to be searched for.- Returns:
- index of the search key, if it is contained in the list;
otherwise, (-(insertion point) - 1). The
insertion point is defined as the point at which the
key would be inserted into the list: the index of the first
element greater than the key, or list.size(), if all
elements in the list are less than the specified key. Note
that this guarantees that the return value will be >= 0 if
and only if the key is found.
- See Also:
sort(long[])
binarySearch
public static int binarySearch(int[] a,
int key)
- Searches the specified array of ints for the specified value using the
binary search algorithm. The array must be sorted (as
by the sort method, above) prior to making this call. If it
is not sorted, the results are undefined. If the array contains
multiple elements with the specified value, there is no guarantee which
one will be found.
- Parameters:
a
- the array to be searched.key
- the value to be searched for.- Returns:
- index of the search key, if it is contained in the list;
otherwise, (-(insertion point) - 1). The
insertion point is defined as the point at which the
key would be inserted into the list: the index of the first
element greater than the key, or list.size(), if all
elements in the list are less than the specified key. Note
that this guarantees that the return value will be >= 0 if
and only if the key is found.
- See Also:
sort(int[])
binarySearch
public static int binarySearch(short[] a,
short key)
- Searches the specified array of shorts for the specified value using
the binary search algorithm. The array must be sorted
(as by the sort method, above) prior to making this call. If
it is not sorted, the results are undefined. If the array contains
multiple elements with the specified value, there is no guarantee which
one will be found.
- Parameters:
a
- the array to be searched.key
- the value to be searched for.- Returns:
- index of the search key, if it is contained in the list;
otherwise, (-(insertion point) - 1). The
insertion point is defined as the point at which the
key would be inserted into the list: the index of the first
element greater than the key, or list.size(), if all
elements in the list are less than the specified key. Note
that this guarantees that the return value will be >= 0 if
and only if the key is found.
- See Also:
sort(short[])
binarySearch
public static int binarySearch(char[] a,
char key)
- Searches the specified array of chars for the specified value using the
binary search algorithm. The array must be sorted (as
by the sort method, above) prior to making this call. If it
is not sorted, the results are undefined. If the array contains
multiple elements with the specified value, there is no guarantee which
one will be found.
- Parameters:
a
- the array to be searched.key
- the value to be searched for.- Returns:
- index of the search key, if it is contained in the list;
otherwise, (-(insertion point) - 1). The
insertion point is defined as the point at which the
key would be inserted into the list: the index of the first
element greater than the key, or list.size(), if all
elements in the list are less than the specified key. Note
that this guarantees that the return value will be >= 0 if
and only if the key is found.
- See Also:
sort(char[])
binarySearch
public static int binarySearch(byte[] a,
byte key)
- Searches the specified array of bytes for the specified value using the
binary search algorithm. The array must be sorted (as
by the sort method, above) prior to making this call. If it
is not sorted, the results are undefined. If the array contains
multiple elements with the specified value, there is no guarantee which
one will be found.
- Parameters:
a
- the array to be searched.key
- the value to be searched for.- Returns:
- index of the search key, if it is contained in the list;
otherwise, (-(insertion point) - 1). The
insertion point is defined as the point at which the
key would be inserted into the list: the index of the first
element greater than the key, or list.size(), if all
elements in the list are less than the specified key. Note
that this guarantees that the return value will be >= 0 if
and only if the key is found.
- See Also:
sort(byte[])
binarySearch
public static int binarySearch(double[] a,
double key)
- Searches the specified array of doubles for the specified value using
the binary search algorithm. The array must be sorted
(as by the sort method, above) prior to making this call. If
it is not sorted, the results are undefined. If the array contains
multiple elements with the specified value, there is no guarantee which
one will be found.
- Parameters:
a
- the array to be searched.key
- the value to be searched for.- Returns:
- index of the search key, if it is contained in the list;
otherwise, (-(insertion point) - 1). The
insertion point is defined as the point at which the
key would be inserted into the list: the index of the first
element greater than the key, or list.size(), if all
elements in the list are less than the specified key. Note
that this guarantees that the return value will be >= 0 if
and only if the key is found.
- See Also:
sort(double[])
binarySearch
public static int binarySearch(float[] a,
float key)
- Searches the specified array of floats for the specified value using
the binary search algorithm. The array must be sorted
(as by the sort method, above) prior to making this call. If
it is not sorted, the results are undefined. If the array contains
multiple elements with the specified value, there is no guarantee which
one will be found.
- Parameters:
a
- the array to be searched.key
- the value to be searched for.- Returns:
- index of the search key, if it is contained in the list;
otherwise, (-(insertion point) - 1). The
insertion point is defined as the point at which the
key would be inserted into the list: the index of the first
element greater than the key, or list.size(), if all
elements in the list are less than the specified key. Note
that this guarantees that the return value will be >= 0 if
and only if the key is found.
- See Also:
sort(float[])
binarySearch
public static int binarySearch(Object[] a,
Object key)
- Searches the specified array for the specified object using the binary
search algorithm. The array must be sorted into ascending order
according to the natural ordering of its elements (as by
Sort(Object[]), above) prior to making this call. If it is
not sorted, the results are undefined. If the array contains multiple
elements equal to the specified object, there is no guarantee which
one will be found.
- Parameters:
a
- the array to be searched.key
- the value to be searched for.- Returns:
- index of the search key, if it is contained in the list;
otherwise, (-(insertion point) - 1). The
insertion point is defined as the point at which the
key would be inserted into the list: the index of the first
element greater than the key, or list.size(), if all
elements in the list are less than the specified key. Note
that this guarantees that the return value will be >= 0 if
and only if the key is found.
- Throws:
- ClassCastException - if the array contains elements that are not
mutually comparable (for example, strings and integers),
or the search key in not mutually comparable with the elements
of the array.
- See Also:
Comparable
,
sort(Object[])
binarySearch
public static int binarySearch(Object[] a,
Object key,
Comparator c)
- Searches the specified array for the specified object using the binary
search algorithm. The array must be sorted into ascending order
according to the specified comparator (as by the Sort(Object[],
Comparator) method, above), prior to making this call. If it is
not sorted, the results are undefined. If the array contains multiple
elements equal to the specified object, there is no guarantee which one
will be found.
- Parameters:
a
- the array to be searched.key
- the value to be searched for.c
- the comparator by which the array is ordered.- Returns:
- index of the search key, if it is contained in the list;
otherwise, (-(insertion point) - 1). The
insertion point is defined as the point at which the
key would be inserted into the list: the index of the first
element greater than the key, or list.size(), if all
elements in the list are less than the specified key. Note
that this guarantees that the return value will be >= 0 if
and only if the key is found.
- Throws:
- ClassCastException - if the array contains elements that are not
mutually comparable using the specified comparator,
or the search key in not mutually comparable with the
elements of the array using this comparator.
- See Also:
Comparable
,
sort(Object[], Comparator)
equals
public static boolean equals(long[] a,
long[] a2)
- Returns true if the two specified arrays of longs are
equal to one another. Two arrays are considered equal if both
arrays contain the same number of elements, and all corresponding pairs
of elements in the two arrays are equal. In other words, two arrays
are equal if they contain the same elements in the same order. Also,
two array references are considered equal if both are null.
- Parameters:
a
- one array to be tested for equality.a2
- the other array to be tested for equality.- Returns:
- true if the two arrays are equal.
equals
public static boolean equals(int[] a,
int[] a2)
- Returns true if the two specified arrays of ints are
equal to one another. Two arrays are considered equal if both
arrays contain the same number of elements, and all corresponding pairs
of elements in the two arrays are equal. In other words, two arrays
are equal if they contain the same elements in the same order. Also,
two array references are considered equal if both are null.
- Parameters:
a
- one array to be tested for equality.a2
- the other array to be tested for equality.- Returns:
- true if the two arrays are equal.
equals
public static boolean equals(short[] a,
short[] a2)
- Returns true if the two specified arrays of shorts are
equal to one another. Two arrays are considered equal if both
arrays contain the same number of elements, and all corresponding pairs
of elements in the two arrays are equal. In other words, two arrays
are equal if they contain the same elements in the same order. Also,
two array references are considered equal if both are null.
- Parameters:
a
- one array to be tested for equality.a2
- the other array to be tested for equality.- Returns:
- true if the two arrays are equal.
equals
public static boolean equals(char[] a,
char[] a2)
- Returns true if the two specified arrays of chars are
equal to one another. Two arrays are considered equal if both
arrays contain the same number of elements, and all corresponding pairs
of elements in the two arrays are equal. In other words, two arrays
are equal if they contain the same elements in the same order. Also,
two array references are considered equal if both are null.
- Parameters:
a
- one array to be tested for equality.a2
- the other array to be tested for equality.- Returns:
- true if the two arrays are equal.
equals
public static boolean equals(byte[] a,
byte[] a2)
- Returns true if the two specified arrays of bytes are
equal to one another. Two arrays are considered equal if both
arrays contain the same number of elements, and all corresponding pairs
of elements in the two arrays are equal. In other words, two arrays
are equal if they contain the same elements in the same order. Also,
two array references are considered equal if both are null.
- Parameters:
a
- one array to be tested for equality.a2
- the other array to be tested for equality.- Returns:
- true if the two arrays are equal.
equals
public static boolean equals(boolean[] a,
boolean[] a2)
- Returns true if the two specified arrays of equals are
equal to one another. Two arrays are considered equal if both
arrays contain the same number of elements, and all corresponding pairs
of elements in the two arrays are equal. In other words, two arrays
are equal if they contain the same elements in the same order. Also,
two array references are considered equal if both are null.
- Parameters:
a
- one array to be tested for equality.a2
- the other array to be tested for equality.- Returns:
- true if the two arrays are equal.
equals
public static boolean equals(double[] a,
double[] a2)
- Returns true if the two specified arrays of doubles are
equal to one another. Two arrays are considered equal if both
arrays contain the same number of elements, and all corresponding pairs
of elements in the two arrays are equal. In other words, two arrays
are equal if they contain the same elements in the same order. Also,
two array references are considered equal if both are null.
Two doubles d1 and d2 are considered equal if:
new Double(d1).equals(new Double(d2))
(Unlike the == operator, this method considers
NaN equals to itself, and 0.0d unequal to -0.0d.)
- Parameters:
a
- one array to be tested for equality.a2
- the other array to be tested for equality.- Returns:
- true if the two arrays are equal.
- See Also:
Double#equals(Double)
equals
public static boolean equals(float[] a,
float[] a2)
- Returns true if the two specified arrays of floats are
equal to one another. Two arrays are considered equal if both
arrays contain the same number of elements, and all corresponding pairs
of elements in the two arrays are equal. In other words, two arrays
are equal if they contain the same elements in the same order. Also,
two array references are considered equal if both are null.
Two doubles d1 and d2 are considered equal if:
new Double(d1).equals(new Double(d2))
(Unlike the == operator, this method considers
NaN equals to itself, and 0.0d unequal to -0.0d.)
- Parameters:
a
- one array to be tested for equality.a2
- the other array to be tested for equality.- Returns:
- true if the two arrays are equal.
- See Also:
Double#equals(Double)
equals
public static boolean equals(Object[] a,
Object[] a2)
- Returns true if the two specified arrays of Objects are
equal to one another. The two arrays are considered equal if
both arrays contain the same number of elements, and all corresponding
pairs of elements in the two arrays are equal. Two objects e1
and e2 are considered equal if (e1==null ? e2==null
: e1.equals(e2)). In other words, the two arrays are equal if
they contain the same elements in the same order. Also, two array
references are considered equal if both are null.
- Parameters:
a
- one array to be tested for equality.a2
- the other array to be tested for equality.- Returns:
- true if the two arrays are equal.
fill
public static void fill(long[] a,
long val)
- Assigns the specified long value to each element of the specified array
of longs.
- Parameters:
a
- the array to be filled.val
- the value to be stored in all elements of the array.
fill
public static void fill(long[] a,
int fromIndex,
int toIndex,
long val)
- Assigns the specified long value to each element of the specified
range of the specified array of longs.
- Parameters:
a
- the array to be filled.fromIndex
- the index of the first element (inclusive) to be
filled with the specified value.toIndex
- the index of the last element (exclusive) to be
filled with the specified value.val
- the value to be stored in all elements of the array.- Throws:
- IllegalArgumentException - if fromIndex > toIndex
- ArrayIndexOutOfBoundsException - if fromIndex < 0 or
toIndex > a.length
fill
public static void fill(int[] a,
int val)
- Assigns the specified int value to each element of the specified array
of ints.
- Parameters:
a
- the array to be filled.val
- the value to be stored in all elements of the array.
fill
public static void fill(int[] a,
int fromIndex,
int toIndex,
int val)
- Assigns the specified int value to each element of the specified
range of the specified array of ints.
- Parameters:
a
- the array to be filled.fromIndex
- the index of the first element (inclusive) to be
filled with the specified value.toIndex
- the index of the last element (exclusive) to be
filled with the specified value.val
- the value to be stored in all elements of the array.- Throws:
- IllegalArgumentException - if fromIndex > toIndex
- ArrayIndexOutOfBoundsException - if fromIndex < 0 or
toIndex > a.length
fill
public static void fill(short[] a,
short val)
- Assigns the specified short value to each element of the specified array
of shorts.
- Parameters:
a
- the array to be filled.val
- the value to be stored in all elements of the array.
fill
public static void fill(short[] a,
int fromIndex,
int toIndex,
short val)
- Assigns the specified short value to each element of the specified
range of the specified array of shorts.
- Parameters:
a
- the array to be filled.fromIndex
- the index of the first element (inclusive) to be
filled with the specified value.toIndex
- the index of the last element (exclusive) to be
filled with the specified value.val
- the value to be stored in all elements of the array.- Throws:
- IllegalArgumentException - if fromIndex > toIndex
- ArrayIndexOutOfBoundsException - if fromIndex < 0 or
toIndex > a.length
fill
public static void fill(char[] a,
char val)
- Assigns the specified char value to each element of the specified array
of chars.
- Parameters:
a
- the array to be filled.val
- the value to be stored in all elements of the array.
fill
public static void fill(char[] a,
int fromIndex,
int toIndex,
char val)
- Assigns the specified char value to each element of the specified
range of the specified array of chars.
- Parameters:
a
- the array to be filled.fromIndex
- the index of the first element (inclusive) to be
filled with the specified value.toIndex
- the index of the last element (exclusive) to be
filled with the specified value.val
- the value to be stored in all elements of the array.- Throws:
- IllegalArgumentException - if fromIndex > toIndex
- ArrayIndexOutOfBoundsException - if fromIndex < 0 or
toIndex > a.length
fill
public static void fill(byte[] a,
byte val)
- Assigns the specified byte value to each element of the specified array
of bytes.
- Parameters:
a
- the array to be filled.val
- the value to be stored in all elements of the array.
fill
public static void fill(byte[] a,
int fromIndex,
int toIndex,
byte val)
- Assigns the specified byte value to each element of the specified
range of the specified array of bytes.
- Parameters:
a
- the array to be filled.fromIndex
- the index of the first element (inclusive) to be
filled with the specified value.toIndex
- the index of the last element (exclusive) to be
filled with the specified value.val
- the value to be stored in all elements of the array.- Throws:
- IllegalArgumentException - if fromIndex > toIndex
- ArrayIndexOutOfBoundsException - if fromIndex < 0 or
toIndex > a.length
fill
public static void fill(boolean[] a,
boolean val)
- Assigns the specified boolean value to each element of the specified
array of booleans.
- Parameters:
a
- the array to be filled.val
- the value to be stored in all elements of the array.
fill
public static void fill(boolean[] a,
int fromIndex,
int toIndex,
boolean val)
- Assigns the specified boolean value to each element of the specified
range of the specified array of booleans.
- Parameters:
a
- the array to be filled.fromIndex
- the index of the first element (inclusive) to be
filled with the specified value.toIndex
- the index of the last element (exclusive) to be
filled with the specified value.val
- the value to be stored in all elements of the array.- Throws:
- IllegalArgumentException - if fromIndex > toIndex
- ArrayIndexOutOfBoundsException - if fromIndex < 0 or
toIndex > a.length
fill
public static void fill(double[] a,
double val)
- Assigns the specified double value to each element of the specified
array of doubles.
- Parameters:
a
- the array to be filled.val
- the value to be stored in all elements of the array.
fill
public static void fill(double[] a,
int fromIndex,
int toIndex,
double val)
- Assigns the specified double value to each element of the specified
range of the specified array of doubles.
- Parameters:
a
- the array to be filled.fromIndex
- the index of the first element (inclusive) to be
filled with the specified value.toIndex
- the index of the last element (exclusive) to be
filled with the specified value.val
- the value to be stored in all elements of the array.- Throws:
- IllegalArgumentException - if fromIndex > toIndex
- ArrayIndexOutOfBoundsException - if fromIndex < 0 or
toIndex > a.length
fill
public static void fill(float[] a,
float val)
- Assigns the specified float value to each element of the specified array
of floats.
- Parameters:
a
- the array to be filled.val
- the value to be stored in all elements of the array.
fill
public static void fill(float[] a,
int fromIndex,
int toIndex,
float val)
- Assigns the specified float value to each element of the specified
range of the specified array of floats.
- Parameters:
a
- the array to be filled.fromIndex
- the index of the first element (inclusive) to be
filled with the specified value.toIndex
- the index of the last element (exclusive) to be
filled with the specified value.val
- the value to be stored in all elements of the array.- Throws:
- IllegalArgumentException - if fromIndex > toIndex
- ArrayIndexOutOfBoundsException - if fromIndex < 0 or
toIndex > a.length
fill
public static void fill(Object[] a,
Object val)
- Assigns the specified Object reference to each element of the specified
array of Objects.
- Parameters:
a
- the array to be filled.val
- the value to be stored in all elements of the array.
fill
public static void fill(Object[] a,
int fromIndex,
int toIndex,
Object val)
- Assigns the specified Object reference to each element of the specified
range of the specified array of Objects.
- Parameters:
a
- the array to be filled.fromIndex
- the index of the first element (inclusive) to be
filled with the specified value.toIndex
- the index of the last element (exclusive) to be
filled with the specified value.val
- the value to be stored in all elements of the array.- Throws:
- IllegalArgumentException - if fromIndex > toIndex
- ArrayIndexOutOfBoundsException - if fromIndex < 0 or
toIndex > a.length
asList
public static List asList(Object[] a)
- Returns a fixed-size list backed by the specified array. (Changes to
the returned list "write through" to the array.) This method acts
as bridge between array-based and collection-based APIs, in
combination with Collection.toArray. The returned list is
serializable.
- Parameters:
a
- the array by which the list will be backed.- Returns:
- a list view of the specified array.
- See Also:
Collection.toArray()
Submit a bug or feature
Java, Java 2D, and JDBC are a trademarks or registered trademarks of Sun Microsystems, Inc. in the US and other countries.
Copyright 1993-1999 Sun Microsystems, Inc. 901 San Antonio Road,
Palo Alto, California, 94303, U.S.A. All Rights Reserved.