Question: I saw [this question](https://stackoverflow.com/questions/2327916/operator-in-java) a few minutes ago, and decided to take a look in the java String class to check if there was some overloading for the `+` operator.

I couldn't find anything, but I know I can do this

```
String ab = "ab";
String cd = "cd";
String both = ab + cd; //both = "abcd"

```

Where's that implemented?

Answer: 
It is handled by the compiler.
`String` is defined as a standard type just like int, double, float, etc. on compiler level. Essentially, all compilers have operator overloading. Operator overloading is not defined for Developers (unlike in C++).

Interestingly enough: This question was logged as a bug: <http://bugs.sun.com/view_bug.do?bug_id=4905919>