In Java 8 '+' operator for concatinating replaced by new StringBuilder()

Question

In Java 8, I wrote some sample code.

String s1 = "Hello";  
String s2 = "world";  
String s3 = s1 + s2;

After decompiling .class file I found that 3rd statement

 String s3 = s1 + s2;

replaced by

 String s3 = new StringBuilder(s1).append(s2).toString();

Does it mean that There is no longer need to use explicit StringBuilder for Optimization and just use '+' operator instead of?

"*Does it mean that There is no longer need to use explicit StringBuilder*" - No, javac uses it in such trivial cases only. In a loop, you still need to use `StringBuilder` youself. — maaartinus, Jun 30 '16 at 12:59
Yes It is right, I wrote some sample program and decompile it and got to know that in loop we need StringBuilder. — shubham12511, Jul 01 '16 at 04:48

score 8 · Accepted Answer · answered Jun 14 '16 at 11:22

8

Yes. Actually, this optimization had been done in Java 6. See Bruce Eckel's "Thinking in Java" 4th edition pp.356-359 for details

answered Jun 14 '16 at 11:22

1 Answers1