Difference between x.toString() and x+“”

Question

Back in college one of my profs. taught us to just do x + \"\" as a quick conversion from basic types to strings.
I don\'t remember which class it was in I

Answer 1

Because strings are immutable, x+"" invokes two functions: x.toString() and StringBuffer.append() (in Java, at least). I imagine most good JITs would simply turn that into a single function call, x.toString(), but I couldn't be sure without actually testing.