concatenation « StringBuffer « Java Data Type Q&A

1. Why to use StringBuffer in Java instead of the string concatenation operator

Someone told me it's more efficient to use StringBuffer to concatenate strings in Java than to use the + operator for Strings. What happens under the hood when you do that? ...

2. Java: StringBuffer & Concatenation

I'm using StringBuffer in Java to concat strings together, like so:

StringBuffer str = new StringBuffer();

str.append("string value");
I would like to know if there's a method (although I didn't find anything from a ...