Character Array in Java

A character array in Java is an array that stores multiple characters (char) in contiguous memory locations. It is useful when you want to manipulate individual characters of a string-like data structure or perform operations such as sorting, searching, or reversing characters.

Example:

class GFG {
    public static void main(String[] args) {
        char[] charArray1 = new char[5];       
        char[] charArray2 = {'a', 'b', 'c', 'd', 'e'};
        System.out.println("Array 1 length: " + charArray1.length);
        System.out.println("Array 2 length: " + charArray2.length);
    }
}

Array 1 length: 5
Array 2 length: 5

Explanation:

• charArray1 = new char[5] creates an empty character array of length 5.
• charArray2 = {'a','b','c','d','e'} creates a character array and assigns values directly.
• charArray.length is used to get and print the length of the arrays.

Declaring a Character Array

char[] charArray;
charArray = new char[10];
or
char[] charArray = new char[10];
or
char[] charArray = {'a', 'b', 'c', 'd', 'e'};

Operations on Character Array in Java

The following are the main operations you can perform on a character array (char[]):

1. Accessing Elements

Use the index to access or modify elements:

charArray[0] = 'f';
System.out.println(charArray[0]);

Example: This program demonstrates how to access and modify elements in a character array in Java.

class GFG {
    public static void main(String[] args) {
        char[] charArray = {'x', 'y', 'z'};
        System.out.println("First element: " + charArray[0]);
        System.out.println("Second element: " + charArray[1]);
        charArray[0] = 'a';
        System.out.println("Modified first element: " + charArray[0]);
    }
}

First element: x
Second element: y
Modified first element: a

Explanation:

• charArray[0] and charArray[1] are used to access elements at index 0 and 1.
• charArray[0] = 'a' modifies the first element of the array.

2. Iterating Over a Character Array

Example 1: This program demonstrates how to iterate over a character array using a standard for loop in Java.

class GFG {
    public static void main(String[] args) {
        char[] charArray = {'H', 'e', 'l', 'l', 'o'};

        for (int i = 0; i < charArray.length; i++) {
            System.out.print(charArray[i] + " ");
        }
        System.out.println();
    }
}

H e l l o 

Explanation:

• for (int i = 0; i < charArray.length; i++) loops through each index of the array.
• charArray[i] accesses the element at the current index i.

Example 2: This program demonstrates how to iterate over a character array using the enhanced for-each loop in Java.

class GFG {
    public static void main(String[] args) {
        char[] charArray = {'H', 'e', 'l', 'l', 'o'};
        for (char c : charArray) {
            System.out.print(c + " ");
        }
    }
}

H e l l o 

Explanation:

• for (char c : charArray) iterates directly over each element of the array.
• c represents the current character in the iteration.

3. Comparing Character Arrays

Example: This program demonstrates how to compare two character arrays for equality using Arrays.equals() in Java.

import java.util.Arrays;
class GFG {
    public static void main(String[] args) {
        char[] arr1 = {'a','b','c','d','e'};
        char[] arr2 = {'a','b','c','d','e'};
        char[] arr3 = {'a','b','c','x','y'};
        if (Arrays.equals(arr1, arr2))
            System.out.println("arr1 and arr2 are equal");
        else
            System.out.println("arr1 and arr2 are not equal");
        if (Arrays.equals(arr1, arr3))
            System.out.println("arr1 and arr3 are equal");
        else
            System.out.println("arr1 and arr3 are not equal");
    }
}

arr1 and arr2 are equal
arr1 and arr3 are not equal

Explanation: Arrays.equals() compares the contents of the arrays, not references.

4. Converting Between Strings and Character Arrays

Example 1: This program demonstrates how to convert a String into a character array in Java.

import java.util.Arrays;
class GFG {
    public static void main(String[] args) {
        String str = "Hello World";
        char[] charArray = str.toCharArray();
        System.out.println("Character Array: " + Arrays.toString(charArray));
    }
}

Character Array: [H, e, l, l, o,  , W, o, r, l, d]

Explanation:

• str.toCharArray() converts the string str into a char array.
• Arrays.toString(charArray) is used to print the array in a readable format.

Example 2: This program demonstrates how to convert a character array into a String in Java.

import java.util.Arrays;
class GFG {
    public static void main(String[] args) {
        char[] charArray = {'H','e','l','l','o'};
        String str = new String(charArray);

        System.out.println("String: " + str);
    }
}

String: Hello

Explanation: new String(charArray) creates a String from the character array charArray.

5. Copying Character Arrays

Example 1: This program demonstrates how to create a full copy of a character array using Arrays.copyOf() in Java.

import java.util.Arrays;
class GFG {
    public static void main(String[] args) {
        char[] original = {'a','b','c','d','e'};
        char[] copy = Arrays.copyOf(original, original.length);
        System.out.println("Original: " + Arrays.toString(original));
        System.out.println("Full Copy: " + Arrays.toString(copy));
    }
}

Explanation:

• Arrays.copyOf(original, original.length) creates a new array copy containing all elements of original.
• Arrays.toString() is used to print arrays in a readable format.
• Changes to copy will not affect the original array since it’s a separate copy.

Related Topics

• Arrays in Java
• Strings in Java
• Loops in Java