Difference between StringBuilder and StringBuffer.

 

In Java, StringBuilder and StringBuffer are both used to create and manipulate strings, but they differ in terms of thread safety and performance characteristics. Here's a comparison of the two with examples:

1. StringBuilder:

   • StringBuilder is not thread-safe, which means it is not synchronized for use in multithreaded environments. If multiple threads try to modify a StringBuilder simultaneously, it may lead to unexpected results.
   • StringBuilder is more efficient than StringBuffer in a single-threaded environment because it does not incur the synchronization overhead.

   Example using StringBuilder:

   java

public class StringBuilderExample {
    public static void main(String[] args) {
        StringBuilder sb = new StringBuilder();
        sb.append("Hello");
        sb.append(" ");
        sb.append("World");
        String result = sb.toString();
        System.out.println(result); // Output: Hello World
    }
}

StringBuffer:

• StringBuffer is thread-safe, meaning it is synchronized for use in multithreaded environments. Multiple threads can safely modify a StringBuffer without conflicts.
• StringBuffer is less efficient than StringBuilder in a single-threaded environment due to the synchronization overhead.

Example using StringBuffer:

java

2. public class StringBufferExample {
       public static void main(String[] args) {
           StringBuffer sb = new StringBuffer();
           sb.append("Hello");
           sb.append(" ");
           sb.append("World");
           String result = sb.toString();
           System.out.println(result); // Output: Hello World
       }
   }
   

In both examples, we create a string by appending "Hello" and "World" together. The main difference lies in the choice of StringBuilder or StringBuffer based on your specific requirements:

• Use StringBuilder when you are working in a single-threaded environment or when you are certain that no concurrent modifications will occur, as it offers better performance.

• Use StringBuffer when you need to ensure thread safety in a multi-threaded environment, even though it may have slightly lower performance in a single-threaded scenario.

The choice between StringBuilder and StringBuffer depends on your application's needs for thread safety and performance.