Strings and StringBuffer

[Suhail Mohammed]

what makes strings immutable and StringBuffer mutable

[Jesper de Jong]

Do you know what "immutable" means?

Class String does not have any methods that change the string itself. Once you have created a String object, the content of the String object cannot be changed. That's why String is immutable.

Class StringBuffer does have a lot of methods that change the internal state of the object. You can append text to a StringBuffer for example. That's why StringBuffer is not immutable.