Could somebody explain why the following functions give different results. The first does not seem to work, but the second does. I'm puzzled because I thought +=1 and ++ did the same thing.
(I'm not intending to actually use this code, it's just to demonstrate the difference).
/*function 1*/
function incrementIfZero1(base,element) {
if (element == 0) {
return base++;
}
else
{
return base;
}
};
/*function 2*/
function incrementIfZero2(base,element) {
if (element == 0) {
return base+=1;
}
else
{
return base;
}
};
incrementIfZero1(1,0) /* -> 1*/
incrementIfZero2(1,0) /* -> 2*/
Any help is very much appreciated.
Thanks,
Robin
[Edit:]
Thank you for your replies, it makes sense now. I had also tried the following statement, which resulted in the same thing as function 1:
return (base++)
I'm now surprised that this doesn't give the same result as function 2 - I would have expected the brackets to 'force' it to be evaluated before returning. Any idea why this is not the case?
when you return base++
it returns the value of base just before it gets incremented. You want to do ++base
to make sure the increment happens first then it gets returned
otherwise ++
is the same as +=1
[edit] in response to your edit, i tried wrapping random statements in parentheses and most mathematical operators respond as expected, this incrementation seems to be exempt, likely because the syntax of pre-incrementation vs post-incrementation is highly intentional and the statement itself returns a specific value regardless of whether or not you wrap it in parentheses