Question

Possible Duplicate:
Why to use StringBuffer in Java instead of the string concatenation operator

what is the advantage or aim of doing this

int a= 42
StringBuffer sb = new StringBuffer(40); 
String s = sb.append("a = ").append(a).append("!").toString(); 
System.out.println(sb);

result > a = 42!

instead of

 int a= 42
 String s = "a = " + a + "!"; 
 System.out.println(sb);

Answer 1

In your scenario, I’m not sure there is a difference b/c all of your “+” are on one line (which only creates a String once). In general, though, Strings are immutable objects and are not truly manipulated but rather created and discarded using StringBuffers.

So ultimately, you will have more efficient code if you use StringBuffers (and generally StringBuilders). If you google “String vs. StringBuffer vs. StringBuilder” you can find many articles detailing the statistics.