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 classclass 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 classclass 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 Characterimport java.io.*;// driver classclass 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 Positionsimport java.io.*;// Driver Classclass 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 Stringimport java.io.*;// Driver Classclass 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); }} |
Output
Count the occurrence of e : 4
References
To know more about more String classes refer to the article String Class in Java.
