Question

I just found my compiler allowed me to write below code and did not raised any compile time error. Could anyone please enlighten me!

double y = arcToFindPointOn.getCenterXY().y - arcToFindPointOn.getRadius()*Math.sin(theta);;

Weird thing about above code line is semi-colon at the very end!

Thanks!

Answer 1

in other languages as well, like C# and C++, having an instruction with only ; means empty instruction and is allowed, generates no errors and simply does nothing.

plenty of articles on this online, found this one: Multiple semicolons are allowed by the C# Compiler for statement termination

This is a little weirdness inherited from C. In fact your example
isn’t a statement terminated by three semicolons, but three
statements, two of which are empty. Occassionally it can be useful to
use the empty statement in e.g. an if statement or a while loop, and
then it would seem arbitrary to disallow it elsewhere. Besides,
changing it now would be an unnecessary breaking change.