从未使用分配的值

Question

Pretty sure the warning means that I declared a variable that I never used elsewhere but I'm almost positive I am using this variable.

The line it highlights is:

return fitIndex = ++i;

Yet if I remove the ++i my code behaves erroneously.

If I do this instead:

fitIndex = ++i;
return fitIndex;

It gives no warnings.

Is there some interaction here with the return statement I'm missing? Doesn't it increment i first, then assign it to fitIndex , and then returns the value?

It doesn't affect my code at all, but just curious.

Answer 1

There doesn't seem to be any purpose to fitIndex (you never access the value, since you return immediately). In other words, the compiler thinks

return fitIndex = ++i;

can be replaced by

return ++i;

tl;dr you can remove fitIndex .