Problems with alternating colors in for loop

chrisdee

Hi,

The script below only echo's alternating colors for the first 4 values of $i.
The rest is echo'ed with black color. Any idea how I can get it to alternate colors also for the other values of $i?

<?php  

$colors = array('lightgreen','lightblue','orange','red');  

for($i = '0'; $i < '50'; $i++) {  

 echo " <span style='color: ".$colors[$i].";'><span style='font-family: Webdings; font-size: 30px; '>&#".$i."</span>&#".$i.";</span>";  

}  

?>

laserlight

Instead of $colors[$i] you should have written $colors[$i % 4].

Shouldn't you be making better use of CSS here, at least for CSS classes? There might even be a way to do this entirely in CSS, though I am afraid that that is beyond me.

Weedpacket

Yeah, the :nth-child selector would cover that requirement.

That said, in the loop, why are [font=monospace]0[/font] and [font=monospace]50[/font] strings instead of integers?

chrisdee

Thank you.

I put the $colors[$i % count($colors)] inside the echo statement. This way I don't have to change the number after % if I increase/decrease the array. I works so I guess it's ok to do ?

<?php 
$colors = array('lightgreen','lightblue','orange','red','magenta'); 

for($i = '0'; $i < '50'; $i++) { 
 echo " <span style='color: ".$colors[$i % count($colors)].";'><span style='font-family: Webdings; font-size: 30px; '>&#".$i."</span>&#".$i.";</span>"; 
} 
?>

chrisdee

Not shure what you mean?
I'm using a for loop to echo all the wingdings between 0 and 50.

dalecosp

Are you referring to the loop with integers in quotes, or the CSS nth-child link?

Generally you don't quote integers in a for loop. I've never tried it, and I'm actually kind of surprised it works, but probably only because I don't follow the PHP Internals list 😉

for ($x = '0'; $x < '30'; $x++) {  // Hmm, this is a "why did ..." moment ...
    foobar();
}
for ($x = 0; $x < 30; $x++) { 
    foobar();
}

In the 2nd loop, the only question is, is whatever you're looping Traversable?

laserlight

dalecosp wrote:
Generally you don't quote integers in a for loop. I've never tried it, and I'm actually kind of surprised it works

Basically an unnecessary conversion from string to integer. It shouldn't be a surprise given that PHP has always been rather weakly typed.

Weedpacket

laserlight wrote:
Basically an unnecessary conversion from string to integer.

Repeatedly - once every time through the loop (in the test), once in the first iteration (when $i is first incremented) , and once more every time the modulus is evaluated.

dalecosp wrote:
I'm actually kind of surprised it works,

What might surprise you more is that

for($i = 'bar'; $i < 'foo'; ++$i)

also works....

dalecosp

laserlight;11052915 wrote:
Basically an unnecessary conversion from string to integer. It shouldn't be a surprise given that PHP has always been rather weakly typed.

Of course, and yeah, weak typing is well-known ... I'm basically just saying "I've never done that, therefore ... $quote " 🙂

I guess I'm a hillbilly hacker at heart: If I ain't seen it, it ain't happened. I'll go get the tinfoil hat before I read the SpaceX news feed. 😃

Weedpacket;11052917 wrote:
What might surprise you more is that
for($i = 'bar'; $i < 'foo'; ++$i)
also works....

I guess it might (yes, it did, but ...) actually I'm doing a "little" fooling on y'all ... I follow at least one PHP list and have read some archived discussion of internals ... there's enough guys there who want (PHP?) to be loved that they're always willing to bend over backwards for any oddball use-case someone can think up or suggest ....

dalecosp

dalecosp;11052921 wrote:
willing to bend over backwards for any oddball use-case someone can think up or suggest ....

I do suppose that coercion of alpha characters would be useful if we ever needed to do math in base26 ....