Question

I’m a newbie in PHP and I’m confused about GET method.

Why the $text in the condition of the loop works with Appserv in Windows 7, but when I tried this code with Xampps on Mac it won’t work I’ve to use for($i=0; $i<strlen($_GET['text']); $i++) instead.

At first, I understand that after I used isset($_GET['text']) so next time I just use only $text, but now I’m confused.

<? $color = array("#FFCCFF", "#FFCCCC", "#FFCC99", "#FF99FF", "#FF99CC",
    "#FF9999", "#FF66FF", "#FF66CC", "#FF6699", "#FF6666");
if (isset($_GET['text'])) { 
    for($i=0; $i<strlen($text); $i++) { 
        $j = $i%10 ?>
        <font color=<?= $color[$j]?>><? echo "$text[$i]"; ?></font>
    } 
} else {
    echo "Empty String";
} ?>

The problem is solved by many of your help.

<?php $color = array("#FFCCFF", "#FFCCCC", "#FFCC99", "#FF99FF", "#FF99CC",
    "#FF9999", "#FF66FF", "#FF66CC", "#FF6699", "#FF6666"); 
if( isset($_GET['text'])) {
    $text = $_GET['text'];
    for( $i=0; $i<strlen($text); $i++) {
        $j = $i%10;
        echo "<font color=$color[$j]>$text[$i]</font>";
    }
} else
    echo "Empty string";
?>

btw I’m trying to use HTML + PHP only because I want to practice with HTML before go in deep with CSS.

Answer 1

The actual answer to your question, if $text is working as an alias for $_GET['text'] is probably that your Windows server is configured with register_globals set to on, which would mean that anything passed over in your query string would be turned into the appropriate variable.

ie. ?awesome=true == $awesome = 'true'

This is bad. Disable register_globals at the offending side, and use $_GET['text'] to access your data.

Your code would look better a little something like this:

<?php
$color = array("#FFCCFF", "#FFCCCC", "#FFCC99", "#FF99FF", "#FF99CC",
                "#FF9999", "#FF66FF", "#FF66CC", "#FF6699", "#FF6666");
if (isset($_GET['text'])) {
    $text = $_GET['text'];
    for($i=0; $i < strlen($text); $i++) { 
        $j = $i % 10; ?>
        <span style="color: <?= $color[$j] ?>"><?= htmlentities($text[$i]); ?></span>
    <?php } 
} else {
    echo "Empty String";
}
?>

Note that I have tidied up your code and made it slightly more sane/safe. htmlentities is used to stop XSS vulns that could come from this, despite being unlikely due to splitting the string. You were mixing up <?php echo .. ?> and <?= .. ?> for some reason, despite them being the exact same thing. Also, don’t use <font>.

You said this:

At first, I understand that “after I used isset($_GET[‘text’]) so next time I just use only($text), but now I’m confused.

If you know you’re mixing them, why are you doing it? If you’re checking for $_GET['text'] being set, then it’s only logical that you would use that for access also.