Java String charAt() method

The charAt(int index) method in Java is used to retrieve the character at a specific index in a string. It is a part of the String class in Java.

To extract a single character from a String, you can refer directly to an individual character via the charAt( ) method. It has this general form:

Syntax:

public char charAt(int index)

Parameters:

index: The index of the character you want to access. The index is 0-based, meaning the first character is at index 0, the second at index 1, and so on.

Return Value: The method returns the character at the specified index in the string.

Example:

public class CharAtExample {
    public static void main(String[] args) {
        String str = "Hello, World!";
        
        // Retrieve the character at index 0 (first character)
        char charAt0 = str.charAt(0);
        System.out.println("Character at index 0: " + charAt0);  // Output: H
        
        // Retrieve the character at index 4 (5th character)
        char charAt7 = str.charAt(7);
        System.out.println("Character at index 7: " + charAt7);  // Output: o
    }
}

Handle StringIndexOutOfBoundsException

This exception is thrown if the index is negative or greater than or equal to the length of the string.

Example:

public class CharAtExceptionExample {
    public static void main(String[] args) {
        String str = "Hello, World!";
        try {
            char invalidChar = str.charAt(18);
        } catch (StringIndexOutOfBoundsException e) {
            System.out.println("Error: " + e.getMessage());  // Output: String index out of range: 18
        }
       
}

Note: If you attempt to access an index that is out of the bounds of the string (such as str.charAt(18)), it will throw a StringIndexOutOfBoundsException.

Java String charAt() method – Interview Questions

Java String charAt() method – Objective Questions (MCQs)

String s = "Java";
System.out.println(s.charAt(2));

String str = "World";
char ch = str.charAt(0);
System.out.println(ch);

Related Java String charAt() method Topics