Variable scope issue

[rlee0001]

This is seriously blowing my mind.

$a = array('a', 'b', 'c');
for ($i=0; $i<=count($a); $i++) {
echo 'In FOR: '.$a[0].' - '.$a[1].' - '.$a[2]."\n";
if ($a[$i] = 'a') {
echo 'In IF: '.$a[0].' - '.$a[1].' - '.$a[2]."\n";
}
}

Ok, I expected the above to output:

In For: a - b - c
In IF: a - b - c
In For: a - b - c
In For: a - b - c

But I get this:

In For: a - b - c
In IF: a - -
In For: a - b - c
In For: a - b - c

For some reason $a[1] & $a[2] can be seen outside the IF but inside the
IF always returns NULL except when the element in the IF is used as a
condition (like $a[0]). I've been coding in PHP for a while now and I
have never noticed IF blocks having their own scope. But I am using an
older version of PHP (4.3.3) on this server (not my choice) which I've
never used before. If IF statements do have their own scope GLOBAL
doesn't fix it because I tried that and got the same results.

I think I'm loosing my mind. Please help.

-Robert

[Oli Filth]

Re: Variable scope issue

rlee0001 said the following on 01/06/2006 18:31:[color=blue]
> This is seriously blowing my mind.
>
> $a = array('a', 'b', 'c');
> for ($i=0; $i<=count($a); $i++) {
> echo 'In FOR: '.$a[0].' - '.$a[1].' - '.$a[2]."\n";
> if ($a[$i] = 'a') {
> echo 'In IF: '.$a[0].' - '.$a[1].' - '.$a[2]."\n";
> }
> }
>[/color]

"==" vs. "="...


--
Oli

[rlee0001]

Re: Variable scope issue

> "==" vs. "="...

Thanks for the quick response Oli. I actually made that error in
creating the example I posted. My orignial code actually does a "!=". I
found that assigning to variables within the FOR works...eg:

$a = $myarray['a'];
$b = $myarray['b'];
$c = $myarray['c'];

Then I can use $a..$c within all structures inside the loop fine. Very
strange.

-Robert

[Chung Leong]

Re: Variable scope issue


Oli Filth wrote:[color=blue]
> rlee0001 said the following on 01/06/2006 18:31:[color=green]
> > This is seriously blowing my mind.
> >
> > $a = array('a', 'b', 'c');
> > for ($i=0; $i<=count($a); $i++) {
> > echo 'In FOR: '.$a[0].' - '.$a[1].' - '.$a[2]."\n";
> > if ($a[$i] = 'a') {
> > echo 'In IF: '.$a[0].' - '.$a[1].' - '.$a[2]."\n";
> > }
> > }
> >[/color]
>
> "==" vs. "="...
>
>
> --
> Oli[/color]

That doesn't explain the problem he/she described. As written, the code
would loop forever, since a new row is added at the end whenever $i ==
count($a).

Obviously we can't diagnose code with typos...

[Bent Stigsen]

Re: Variable scope issue

rlee0001 wrote:[color=blue][color=green]
>> "==" vs. "="...[/color]
>
> Thanks for the quick response Oli. I actually made that error in
> creating the example I posted. My orignial code actually does a "!=". I
> found that assigning to variables within the FOR works...eg:
>
> $a = $myarray['a'];
> $b = $myarray['b'];
> $c = $myarray['c'];
>
> Then I can use $a..$c within all structures inside the loop fine. Very
> strange.[/color]

It really shouldn't be necessary. Give your code that produced the
erroneous output another look, or post it here.

/Bent