Java .sort()

The .sort() method is used to sort arrays of primitive types and objects. The sorting is done in ascending order by default, but it can be customized for objects by implementing the Comparable interface or using a Comparator.

Syntax

Here’s a basic syntax of how to use the .sort() method:

Arrays.sort(array, comparator);

The optional comparator argument is an object that implements the Comparator interface, defining the comparison logic for elements in the array.

Examples

Example 1

In this example, the Arrays.sort(numbers) method is used to sort the array of integers in ascending order. The result is then printed using Arrays.toString():

import java.util.Arrays;

public class Main {
  public static void main(String[] args) {
    int[] numbers = {5, 2, 8, 1, 3};

    // Sorting the array in ascending order
    Arrays.sort(numbers);
    System.out.println("Sorted Array: " + Arrays.toString(numbers));
  }
}

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The above example will give the following output:

Sorted Array: [1, 2, 3, 5, 8]

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Note: For an array of objects, a custom comparator can be used or the objects in the array should implement the Comparable interface.

Example 2

In this example, strings implements the Comparable interface, so they can be sorted directly using Arrays.sort():

import java.util.Arrays;

public class Main {
  public static void main(String[] args) {
    String[] names = {"Alice", "Bob", "Charlie", "David"};

    // Sorting the array of strings in ascending order
    Arrays.sort(names);

    // Printing the sorted array
    System.out.println("Sorted Array: " + Arrays.toString(names));
  }
}

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The above example will give the following output:

Sorted Array: [Alice, Bob, Charlie, David]

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Note: For a custom sorting order, the Comparator interface can be used. Here’s an example of sorting strings by their length.

Example 3

In this example, Comparator.comparing(String::length) is used to sort the array of strings based on their length:

import java.util.Arrays;
import java.util.Comparator;

public class Main {
  public static void main(String[] args) {
    String[] names = {"Alice", "Bob", "Charlie", "David"};

    // Sorting the array of strings by length
    Arrays.sort(names, Comparator.comparing(String::length));
    System.out.println("Sorted Array by Length: " + Arrays.toString(names));
  }
}

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The above example will give the following output:

Sorted Array by Length: [Bob, Alice, David, Charlie]

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