Java Arrays sort(int[] a) Method

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Description

The Java Arrays sort(int[] a) method sorts the specified array of ints into ascending numerical order. This method using a Dual-Pivot Quicksort algorithm which breaks the array into subarrays, sorted them and then merged to give a sorted array.

Declaration

Following is the declaration for java.util.Arrays.sort(int[] a) method

public static void sort(int[] a)

Parameters

a − This is the array to be sorted.

Return Value

This method does not return any value.

Exception

NA

Java Arrays sort​(int[] a, int fromIndex, int toIndex) Method

Description

The Java Arrays sort(int[] a, int fromIndex, int toIndex) method sorts the specified range of given array of ints into ascending numerical order. This method using a Dual-Pivot Quicksort algorithm which breaks the array into subarrays, sorted them and then merged to give a sorted array.

Declaration

Following is the declaration for java.util.Arrays.sort(int[] a, int fromIndex, int toIndex) method

public static void sort​(int[] a, int fromIndex, int toIndex)

Parameters

• a − This is the array to be sorted.

• fromIndex − This is the index of the first element, inclusive, to be sorted.

• toIndex − This is the index of the last element, exclusive, to be sorted

Return Value

This method is not returning anything.

Exception

• IllegalArgumentException − if fromIndex > toIndex

• ArrayIndexOutOfBoundsException − if fromIndex < 0 or toIndex > array.length

Sorting an Array of ints Example

The following example shows the usage of Java Arrays sort(int[]) method. First, we've created an array of ints, printed the original array. Using sort() method, array is sorted and printed thereafter.

package com.tutorialspoint;

import java.util.Arrays;

public class ArrayDemo {
   public static void main(String[] args) {
      // initialize unsorted array
      int arr[] = { 11, 54, 23, 32, 15, 24, 31, 12 };

      System.out.print("Original Array: [");
      // print the array
      for (int i = 0; i < arr.length; i++) {
         System.out.print(arr[i] + " ");
      }
      System.out.println("]");
     
      // sort the array
      Arrays.sort(arr);

      System.out.print("Sorted Array: [");
      // print the array
      for (int i = 0; i < arr.length; i++) {
         System.out.print(arr[i] + " ");
      }
      System.out.println("]");
   }
}

Output

Let us compile and run the above program, this will produce the following result −

Original Array: [11 54 23 32 15 24 31 12 ]
Sorted Array: [11 12 15 23 24 31 32 54 ]

Sorting an Array of ints using Range Example

The following example shows the usage of Java Arrays sort(int[], int, int) method. First, we've created an array of ints, printed the original array. Using sort() method, array is sorted and printed thereafter.

package com.tutorialspoint;

import java.util.Arrays;

public class ArrayDemo {
   public static void main(String[] args) {
      // initialize unsorted array
      int arr[] = { 11, 54, 23, 32, 15, 24, 31, 12 };

      System.out.print("Original Array: [");
      // print the array
      for (int i = 0; i < arr.length; i++) {
         System.out.print(arr[i] + " ");
      }
      System.out.println("]");
     
      // sort the array
      Arrays.sort(arr, 0, arr.length);

      System.out.print("Sorted Array: [");
      // print the array
      for (int i = 0; i < arr.length; i++) {
         System.out.print(arr[i] + " ");
      }
      System.out.println("]");
   }
}

Output

Let us compile and run the above program, this will produce the following result −

Original Array: [11 54 23 32 15 24 31 12 ]
Sorted Array: [11 12 15 23 24 31 32 54 ]

Sorting a Sub-Array of ints Example

The following example shows the usage of Java Arrays sort(int[], int, int) method. First, we've created an array of ints, printed the original array. Using sort() method, a sub-array is sorted and printed thereafter.

package com.tutorialspoint;

import java.util.Arrays;

public class ArrayDemo {
   public static void main(String[] args) {
      // initialize unsorted array
      int arr[] = { 11, 54, 23, 32, 15, 24, 31, 12 };

      System.out.print("Original Array: [");
      // print the array
      for (int i = 0; i < arr.length; i++) {
         System.out.print(arr[i] + " ");
      }
      System.out.println("]");
     
      // sort first five elements of the array 
      Arrays.sort(arr, 0, 5);

      System.out.print("Sorted Array: [");
      // print the array
      for (int i = 0; i < arr.length; i++) {
         System.out.print(arr[i] + " ");
      }
      System.out.println("]");
   }
}

Output

Let us compile and run the above program, this will produce the following result −

Original Array: [11 54 23 32 15 24 31 12 ]
Sorted Array: [11 15 23 32 54 24 31 12 ]