What is the use of StringBuilder class in java?

In Java, StringBuilder is a class that provides a more efficient way to build strings compared to using the + operator or String concatenation. This is because the + operator and String concatenation create a new string object every time a concatenation is performed, which can be inefficient for building large strings. StringBuilder avoids this problem by providing a mutable buffer for constructing strings.

Here's an example of using StringBuilder in Java:

In this example, we create a new StringBuilder object and append two strings to it using the append() method. Then, we convert the StringBuilder object to a String using the toString() method, and finally, we print the resulting string to the console.

The output of this program will be:

This example demonstrates how to build a string using StringBuilder by appending strings together, which is more efficient than using the + operator or String concatenation. Additionally, StringBuilder provides other methods for manipulating the buffer, such as insert(), delete(), and replace(), which can be useful for more complex string manipulation.