Java StringBuffer charAt() Method Last Updated : 23 Jul, 2025 Comments Improve Suggest changes 2 Likes Like Report The charAt() method in the StringBuffer class in Java is used to retrieve the character at a given index in a StringBuffer object. This method allows us to access individual characters in a StringBuffer by specifying the index.Example 1: Here, we will use a valid index to retrieve a character from the StringBuffer object. Java // Java program to demonstrate charAt() method public class CharAt { public static void main(String[] args) { StringBuffer b = new StringBuffer("Java Programming"); // Using charAt() to get the // character at index 5 char ch = b.charAt(5); System.out.println("" + ch); } } OutputP Syntax of charAt() Methodpublic char charAt(int index)Parameters: index: This is an integer representing the index of the character to be fetched.Return Type: char: The character at the specified index.Example 2: If we use charAt() with a Negative Index a StringIndexOutOfBoundsException is thrown, as negative indices are not allowed. Java // Java program to demonstrate // invalid negative index in charAt() public class CharAt { public static void main(String[] args) { StringBuffer b = new StringBuffer("Java Programming"); try { // Using a negative index System.out.println("Character at index -1: " + b.charAt(-1)); } catch (StringIndexOutOfBoundsException e) { System.out.println("Exception: " + e); } } } OutputException: java.lang.StringIndexOutOfBoundsException: index -1,length 16 Example 3: If we pass an index greater than or equal to the length of the StringBuffer object will also result in a StringIndexOutOfBoundsException. Java // Java program to demonstrate invalid index // greater than length in charAt() public class CharAt { public static void main(String[] args) { StringBuffer b = new StringBuffer("Java Programming"); try { // Using an index greater than the length of the buffer System.out.println("Character at index 20: " + b.charAt(20)); } catch (StringIndexOutOfBoundsException e) { System.out.println("Exception: " + e); } } } OutputException: java.lang.StringIndexOutOfBoundsException: index 20,length 16 Create Quiz Comment J juhisrivastav Follow 2 Improve J juhisrivastav Follow 2 Improve Article Tags : Java Java-Strings java-StringBuffer Explore Java BasicsIntroduction to Java3 min readJava Programming Basics9 min readJava Methods6 min readAccess Modifiers in Java4 min readArrays in Java7 min readJava Strings7 min readRegular Expressions in Java3 min readOOP & InterfacesClasses and Objects in Java5 min readAccess Modifiers in Java4 min readJava Constructors4 min readJava OOP(Object Oriented Programming) Concepts10 min readJava Packages2 min readJava Interface7 min readCollectionsCollections in Java12 min readCollections Class in Java13 min readCollection Interface in Java4 min readIterator in Java4 min readJava Comparator Interface4 min readException HandlingJava Exception Handling6 min readJava Try Catch Block4 min readJava final, finally and finalize4 min readChained Exceptions in Java3 min readNull Pointer Exception in Java5 min readException Handling with Method Overriding in Java4 min readJava AdvancedJava Multithreading Tutorial3 min readSynchronization in Java7 min readFile Handling in Java4 min readJava Method References9 min readJava 8 Stream Tutorial7 min readJava Networking6 min readJDBC Tutorial5 min readJava Memory Management4 min readGarbage Collection in Java6 min readMemory Leaks in Java3 min readPractice JavaJava Interview Questions and Answers15+ min readJava Programs - Java Programming Examples7 min readJava Exercises - Basic to Advanced Java Practice Programs with Solutions5 min readJava Quiz1 min readJava Project Ideas For Beginners and Advanced15+ min read Like