Arrays
The Arrays class
Methods
The Arrays class
java.util.Arrays
The Arrays class contains many useful methods for manipulating arrays
The methods of the Arrays class
- All of these methods accept arrays of primitive data types and arrays of objects for the arrayName argument.
- The methods all accept primitive types and objects for the value argument.
- All of the index arguments must be int types.
- If an index argument is less than zero or greater than one less than the length of the array, the method will throw an ArrayIndexOutOfBoundsException.
- If you use the sort method on an array of objects created from a user-defined class, the class must implement the Comparable interface.
Static methods of the Arrays class
| Method | Description |
|---|---|
| fill(arrayName, value) | Fills all elements of the array with the specified value. |
| fill(arrayName, index1, index2, value) | Fills elements of the array with the specified value from the index1 element to, but not including, the index2 element. |
| equals(arrayName1, arrayName2) | Returns a boolean true value if both arrays are of the same type and all of the elements are equal to each other. |
| copyOf(arrayName, length) | Copies the specified array, truncating or padding with default values as needed so the copy has the specified length. |
| copyOfRange(arrayName, index1, index2) | Copies the specified range of the specified array into a new array. |
| sort(arrayName) | Sorts the elements into ascending order. |
| sort(arrayName, index1, index2) | Sorts the elements into ascending order from the index1 element to, but not including, the index2 element. |
| binarySearch(arrayName, value) | Returns an int value for the index of the specified value in the specified array; returns a negative number if the specified value is not found. Array must first be sorted by the sort method. |