StringBuilder vs String concatenation in toString() in Java

Question

Given the 2 toString() implementations below, which one is preferred:

public String toString(){
    return \"{a:\"+ a + \", b:\" + b + \", c: \"         


        

Answer 1

I think we should go with StringBuilder append approach. Reason being :

1. The String concatenate will create a new string object each time (As String is immutable object) , so it will create 3 objects.

2. With String builder only one object will created[StringBuilder is mutable] and the further string gets appended to it.