String charAt() method in Java returns the character at the specified index in a string. The Index of the first character in a string is 0, the second character is 1, and so on. The index value should lie between 0 and length() - 1.
If the index value is greater than or equal to the string length or negative number it returns stringIndexOutOfBoundsException
Example 1:
Java
class Geeks {
public static void main(String args[]) {
// Define a string
String s = "Java String charAt() example";
// Retrieve and print the character at index 8
char ch = s.charAt(8);
System.out.println(ch);
// Retrieve and print the character at index 24
ch = s.charAt(24);
System.out.println(ch);
}
}
Syntax of charAt() Method
public char charAt(int index)
- Parameter: index - Index of the character to be returned.
- Returns: Returns the character at the specified position.
- Exceptions : StringIndexOutOfBoundsException - If the index is negative or greater than the length of the String.
Example 2: The following program demonstrating the Exception case as StringIndexOutOfBoundsException.
Java
class Geeks {
// main function
public static void main(String args[])
{
String s = "abc";
char ch = s.charAt(4);
System.out.println(ch);
}
}
Example 3: Accessing the First and Last Character
Java
import java.io.*;
class Geeks {
// main function
public static void main(String[] args)
{
String str = "GeeksforGeeks";
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));
}
}
Example 4: Print Characters Presented at Odd Positions and Even Positions
Java
import java.io.*;
class Geeks {
public static void main(String[] args)
{
String str = "GeeksforGeeks";
// 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));
}
}
}
Example 5: Counting Frequency of a Character in a String
Java
import java.io.*;
class Geeks {
public static void main(String[] args)
{
String str = "GeeksforGeeks";
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);
}
}
