Java String charAt() Method

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The Java String charAt() method returns the character at the specified index. The index value should lie between 0 and length() – 1. Let us check more points about the String charAt() method in Java.

Syntax of charAt() Java method

public char charAt(int index)

Parameters

index: Index of the character to be returned.

Return Type

Returns the character at the specified position.

Exceptions

StringIndexOutOfBoundsException– If the index is negative or greater than the length of the String.

Example of Java String charAt()

The following examples demonstrate how to use charAt() method:

Example 1:

To show the working of the charAt() method

Java

// Java program to demonstrate
// working of charAt() method
 
// driver class
class Gfg {
    // main function
    public static void main(String args[])
    {
        String s = "Welcome! to Geeksforgeeks Planet";
 
        char ch = s.charAt(3);
        System.out.println(ch);
 
        ch = s.charAt(0);
        System.out.println(ch);
    }
}

Output

c
W

Example 2:

The following program demonstrates the StringIndexOutOfBoundsException.

Java

// Java program to demonstrate
// working of charAt() method
 
// Driver class
class Gfg {
    // main function
    public static void main(String args[])
    {
        String s = "abc";
 
        char ch = s.charAt(4);
        System.out.println(ch);
    }
}

Output

Exception in thread "main" java.lang.StringIndexOutOfBoundsException: String index out of range: 4
    at java.lang.String.charAt(String.java:658)
    at Gfg.main(File.java:9)

Programs for charAt Java Method

1. Accessing the First and Last Character using the charAt() Java method

Java

// Java Program to implement
// Accessing the First and Last Character
import java.io.*;
 
// driver class
class GFG {
    // main function
    public static void main(String[] args)
    {
        String str = "Lazyroar";
        int len = str.length();
 
        // First Element
        System.out.println("First Element: "
                           + str.charAt(0));
 
        // Last Element
        System.out.println("First Element: "
                           + str.charAt(len - 1));
    }
}

Output

First Element: G
First Element: s

2. Print Characters Presented at Odd Positions and Even Positions using charAt() Java method

Java

// Java Program to implement
// Print Characters Presented at
// Odd Positions and Even Positions
import java.io.*;
 
// Driver Class
class GFG {
    // main function
    public static void main(String[] args)
    {
        String str = "Lazyroar";
 
        // Odd Positions
        System.out.println("Odd Positions");
        for (int i = 0; i < str.length(); i += 2) {
            System.out.print(str.charAt(i));
        }
 
        System.out.println("\n");
 
        // Even Positions
        System.out.println("Even Positions");
        for (int i = 1; i < str.length(); i += 2) {
            System.out.print(str.charAt(i));
        }
    }
}

Output

Odd Positions
GesoGes

Even Positions
ekfrek

3. Counting Frequency of a Character in a String using Java charAt() method

Java

// Java Program to implement
// Counting Frequency of a Character
// in a String
import java.io.*;
 
// Driver Class
class GFG {
    // main function
    public static void main(String[] args)
    {
        String str = "Lazyroar";
        int count = 0;
 
        for (int i = 0; i < str.length(); i++) {
            // Counting e in string
            if (str.charAt(i) == 'e')
                count++;
        }
 
        // printing occurrence
        System.out.println("Count the occurrence of e : "
                           + count);
    }
}