PHP Variable Scope Weird Trouble

Question

I was coding PHP when suddenly Im being confused with variable scopes.

If I do the loop like this ...

function foo()
{

    $ctr = 0;

    for ($i = 0 ; $i > 8 ; $i++)
    {

        $ctr = $ctr + 1;

    }

    return $ctr;

}

$ctr returns a 0.

But if I do the loop like this ...

function foo()
{
    $collections = //This has 7 counts;        

    $ctr = 0;

    foreach ($collections as $collection)
    {
         $ctr = $ctr + 1;
    }

    return $ctr;

}

CTR IS RETURNING 7!

So what's is the problem in the first loop?

In your first iteration you say: 0 > 8 -> IF TRUE enter the loop ELSE don't run the loop — Rizier123
– Rizier123, Commented Jul 28, 2015 at 15:16
$i is never higher than 8 in your case, hence the if is getting "skipped". So yes, the problem is in the first loop, and it actually is that the condition you wanted is probably $i < 8 instead. — briosheje
– briosheje, Commented Jul 28, 2015 at 15:24
Oh yeah! the loop is not being called at all! Thanks Guys! :D — tanhernandez
– tanhernandez, Commented Jul 28, 2015 at 15:26

ThomasVdBerge · Accepted Answer · 2015-07-28 15:23:08Z

1

The for loop you are trying to do seems to be a bit wrong.

    for ($i = 0 ; $i > 8 ; $i++)
                  ^^^^^^

Means, Set $i to 0. For as long as $i is bigger than 8, do this loop then increment.

Since $i is set to 0, the condition is never met, so the loop is never executed.

Change $i > 8 to $i < 8.

answered Jul 28, 2015 at 15:23

ThomasVdBerge

8,1985 gold badges48 silver badges64 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Marc B · Accepted Answer · 2015-07-28 15:22:35Z

0

Your loop condition:

for ($i = 0 ; $i > 8 ; $i++)
              ^^^^^^

since the loop starts at 0, you have 0 > 8, which is false, and your loop terminates immediately. Remember, loops terminate when that 2nd argument becomes false. it has to be TRUE for the loop body to execute.

answered Jul 28, 2015 at 15:22

Marc B

362k44 gold badges433 silver badges508 bronze badges

Comments

Wahib Mkadmi · Accepted Answer · 2015-07-28 15:22:49Z

0

The problem in the first loop might be hard to spot, I must say.

It's about the $i > 8, your code doesn't even enter the loop. Invert the operator, ($i = 0 ; $i < 8 ; $i++)

This worked for me.

answered Jul 28, 2015 at 15:22

Wahib Mkadmi

6442 gold badges9 silver badges27 bronze badges

1 Comment

tanhernandez Over a year ago

Thanks so much for this one, helped a lot :)

Collectives™ on Stack Overflow

PHP Variable Scope Weird Trouble

3 Answers 3

Comments

Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related