ToCharArray

Consider a string: it is immutable and cannot be changed. But an array can be changed. With toCharArray we get a char array from a string.

With this method, we change a string into a mutable form. We can modify letters in the array. Then we convert it back into a String.

Example program

Here we begin with a String that contains the letters "abc." Then we call toCharArray on it. We print this array with Arrays.toString.

import java.util.Arrays;

public class Program {
    public static void main(String[] args) {

        String letters = "abc";

        // Convert String to a char array.
        char[] array = letters.toCharArray();
        System.out.println(Arrays.toString(array));

        // Modify the array.
        array[0] = 'A';
        System.out.println(Arrays.toString(array));

        // Get the String.
        String result = new String(array);
        System.out.println(result);
    }
}
[a, b, c]
[A, b, c]
Abc

Notes, toCharArray

Some string manipulations are not simple. We cannot just use insert() or replace() for all things. With toCharArray we can change characters.

Notes, methods

Code that uses toCharArray can be hard to read. For this reason, placing it in a method can be helpful. These methods can receive a String and return a modified one.

A summary

With toCharArray we have a built-in way to get characters from a String. We do not need to get characters in a loop—we can get them all at once from a Java method.