Core Java

What the function of replace(int startIndex, int endIndex, String str) method of StringBuilder class in java?

This is used to replace the string from specified startIndex and endIndex.

What the function of insert(int offset, String s) method of StringBuilder class in java?

What the function of append(String s) method of StringBuilder class in java?

What is the importance of StringBuilder(int length) constructor of StringBuilder class in java?

What is the importance of StringBuilder(String str) constructor of StringBuilder class in java?

What is the importance of StringBuilder() constructor of StringBuilder class in java?