Script not working

[Vivid Lust]

When there is no value in the input, the $pixel is displayed, and i dont want it to!!

 

Problem with the IF statement?? !

 

Please help!

 

Thanks!

 

Code:

 

<?php

// variables
$rate = "2";

// set image source
$img = "http://www.phpfreaks.com/forums/Themes/default/images/on.gif";

// configure image attibutes
list($width, $height, $type, $attr) = getimagesize($img);
$pixels = $width*$height;

// echo values
if( $_POST['url'] != "")
{
echo $pixels;
}


?>
<form action="index.php" method="post">
<input type="text" name="url">
<input type="submit" value="Go!">
</form>

[darkfreaks]

<?php
if( $_POST['url'] = "")
{ }else{
echo $pixels;
}?>

[phpSensei]

<?php
if( $_POST['url'] = "")
{ }else{
echo $pixels;
}?>

 

You never use one '=' in a condition.

[toplay]

You never use one '=' in a condition.

 

Never is harsh...there are some situations where it's nice to use, however, of course I do agree with you in this "if" condition case it's incorrectly used.

 

To avoid this mistake in the future, code constant values on the left side of the condition. That way PHP will generate an error in case one forgets and uses one equal sign instead of two. Example:

 

if ('value' = $_POST['url']) {}  // This will produce an error (good)

 

if ($_POST['url'] = 'value') {}  // This will NOT produce an error and will always evaluate to true (bad)

 

 

Vivid Lust, I'm not sure what you're trying to do with this code and the "url" value (it's not being used). Here is a little better way to go:

 

<?php

$strSubmitted = isset($_POST['submitted']) ? $_POST['submitted'] : '';

// Check if form has been submitted first
if (!empty($strSubmitted)) {   // or can check for specific value: Go!

    $strUrl = isset($_POST['url']) ? $_POST['url'] : '';

    // variables
    $rate = "2";

    // Instead of hard coding this url did you mean to use the url from the form?
    // i.e.  $img = $strUrl
    $img = "http://www.phpfreaks.com/forums/Themes/default/images/on.gif";

    // configure image attibutes
    list($width, $height, $type, $attr) = getimagesize($img);
    $pixels = $width*$height;

    // echo pixels when url value is not empty
    if (!empty($strUrl)) {
        echo $pixels;
    }
}

?>

<form action="index.php" method="post">
<input type="text" name="url">
<input type="submit" value="Go!" name="submitted">
</form>

 

[phpSensei]

I find this hard to believe, it would be just the same if you used '=='

[toplay]

I find this hard to believe, it would be just the same if you used '=='

 

I don't understand your comment/point. Post an example of what you're referring to.

 

 

[laffin]

toplays point is that php will stop with an error, cuz ya can't assigned a variable to a constant.

thus having the constant on the left hand side of the comparisons.

 

if($val=123)

will not generate an error, as $val is assigned 123, and continue with whatever code is in the if statement

 

if(123=$val)

will generate an error, giving u a chance to fix it

[phpSensei]

I find this hard to believe, it would be just the same if you used '=='

 

I don't understand your comment/point. Post an example of what you're referring to.

 

 

 

whats with all the confusion? why doesnt he just use double '='?

 

Woudl

 

<?php
if( $_POST['url'] = "")
{ }else{
echo $pixels;
}?>

 

make a difference with

 

<?php
if( $_POST['url'] == "")
{ }else{
echo $pixels;
}?>

 

or

 

<?php
if('value' == $_POST['value'])
{ }else{
echo $pixels;
}?>

[toplay]

whats with all the confusion? why doesnt he just use double '='?

 

LOL...yes he can use double equal signs. The confusion is your post with the comment I already indicated. I still don't understand what you meant by: "I find this hard to believe, it would be just the same if you used '=='"

 

What is hard for you to believe?  and what would be the same if you used '=='?

 

Why post such a thing?