PHP variable scope and IFs

Question

I have roughtly something similar to this:

function get_gender ($gid){ 
    $return= '';

...some code ..

    if ($male !== 0 && $female !== 0){
        $return = 'mixed';
    }else if ($male !== 0 && $female == 0){
        $return = 'male';
    }
    return $return;

}

I know for a fact that one of the condition is met, so i assumed the $return variable would be updated. Though it always comes back empty. Is this a problem of scope ?

If $male === 0, it will not enter either of those conditions. Do an echo inside the if else blocks to see if PHP ever gets there — NullUserException
– NullUserException, Commented Sep 12, 2011 at 14:02
Also, why don't you do an explicit return from the if-else block instead of having this $return variable? It will save you a couple of steps, a variable and IMO it's cleaner. — NullUserException
– NullUserException, Commented Sep 12, 2011 at 14:06
@NullUserException: there used to be (maybe still is) a school of thought that says a function should have only one return point, so what silkAdmin does is exactly what is recommended by this school. — Colin Fine
– Colin Fine, Commented Sep 12, 2011 at 14:13

Ned Batchelder · Accepted Answer · 2011-09-12 14:01:21Z

4

In your code, if $male is zero, $female is never checked, and neither assignment is run, leaving $return empty.

answered Sep 12, 2011 at 14:01

Ned Batchelder

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1 Comment

blablabla Over a year ago

Thanks, it was actually coming from how i was loading the variable i was checking.. Nothing to do with the code though you all made good points ! Thanks again

CodeCaster · Accepted Answer · 2011-09-12 14:02:21Z

1

No, it's a debugging problem. Scope has nothing to do here since it doesn't change (at least not in the code you provided).

Try this:

if ($male !== 0 && $female !== 0){
    $return = 'mixed';
    echo 'Return: ' . $return;
}else if ($male !== 0 && $female == 0){
    $return = 'male';
    echo 'Return: ' . $return;
} else {
    echo 'None of the conditions met';
}

Besides, don't you want booleans for this (true, false) instead of explicit integer checking?

answered Sep 12, 2011 at 14:02

CodeCaster

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Comments

Jason McCreary · Accepted Answer · 2011-09-12 14:02:32Z

1

No scope should not be a problem here.

More than likely your problem lies in your conditions. Particularly the use of strict equality (i.e. !==).

answered Sep 12, 2011 at 14:02

Jason McCreary

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Comments

oezi · Accepted Answer · 2011-09-12 17:14:31Z

0

nope, this isn't a scope-problem. your variables must be set wrong, so the conditions arn't met. maybe thats because the result should be a female (i can't see an option for that), or it's because you're using explicit type-sensitive conditions(maybe your variables contain strings ander - try to make === to == and !== to == and see if something changes)

to proof this, try to add another else{ } and set $return to "oh noez" (or something else).

edited Sep 12, 2011 at 17:14

answered Sep 12, 2011 at 14:08

oezi

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