String valueOf vs concatenation with empty string

Question

I am working in Java code optimization. I\'m unclear about the difference between String.valueOf or the +\"\" sign:

int intVar = 1;         


        

Answer 1

The first line is equivalent to

String strVal = String.valueOf(intVar) + "";

so that there is some extra (and pointless) work to do. Not sure if the compiler optimizes away concatenations with empty string literals. If it does not (and looking at @Jigar's answer it apparently does not), this will in turn become

String strVal = new StringBuilder().append(String.valueOf(intVar))
                      .append("").toString();

So you should really be using String.valueOf directly.