Why does this piece of code not work ?

Hello all,

I'm having a small problem to do with checkboxes.

Here is the code :

        <input name="homelink" type="checkbox" id="homelink" value="<?php $homelink; ?>"
        <?php if($homelink = 1) { echo"checked"; } elseif($homelink !=1) { echo"unchecked"; } ?>/>

Code (markup):

$homelink can only be 1 or 0 (true or false) and yet when I view this code online the box is checked despite $homelink being set at 0 in the database.

Any ideas ?

Huge Thanks,
Stephen

 

You are doing assignment, not comparison....

E.G if( $homelink = 1)

You are assigning your variable to 1 not comparing the left and right hand side.......

For comparison, you shuold use;

if($homelink == 1)

Code (markup):

No. (1 or 0) and (true or false) are technically different things (though may give similar results.

<?php
$int = 1;
$bool = true;

if($int == 1) print "int is one\n";
if($int === 1) print "int is int(one)\n";
if($int == true) print "int is true\n";
if($int === true) print "int is boolean true\n";

if ($bool == 1) print "bool is one\n";
if ($bool === 1) print "bool is int(one)\n";
if ($bool == true) print "bool is true\n";
if ($bool === true) print "bool is boolean true\n";
?>

PHP:

Output:

int is one
int is int(one)
int is true
bool is one
bool is true
bool is boolean true

Code (markup):

 

Hi,

Thanks for your detailed explanation, much appreciated.

One issue now, I've changed the code to :

        <input name="homelink" type="checkbox" id="homelink" value="<?php $homelink; ?>"
        <?php if($homelink == 1) { echo"checked"; } elseif($homelink !==1) { echo"unchecked"; } ?>/>

Code (markup):

However, I modify $homelink so it's $homelink=1 in the database
But still the box remains unchecked,
However when i changed $homelink to $homelink=0 in the database
The box remains unchecked (what I want)

So i'm baffled. Any thoughts ? It's probably me doing something wrong.

 

Hi Stephen,

No problem at all.

You dont need the !== on the second comparison (only on 'equals' comparisons) so that is fine as !=

I have tried your code here and it seems to be fine - I set the homelink value at the top of the code.

<?php $homelink = 0; ?>

PHP:

Output: <input name="homelink" type="checkbox" id="homelink" value="" unchecked/>

<?php $homelink = 1; ?>

PHP:

Output: <input name="homelink" type="checkbox" id="homelink" value="" checked/>

After updating the value from the database, you are selecting it out somewhere above the code you pasted I assume - what is the value returned as ?

 

perhaps "==" for comparing ??

<input name="homelink" type="checkbox" id="homelink" value="<?php $homelink; ?>"
<?php if($homelink == 1) { echo"checked"; } elseif($homelink !=1) { echo"unchecked"; } ?>/>

actually you could try with a negative condition;

<input name="homelink" type="checkbox" id="homelink" value="<?php $homelink; ?>"
<?php if($homelink != 0) { echo"checked"; } else { echo"unchecked"; } ?>/>

 

Right, I've finally fixed this.

Sadly the solution was alot easier then I expected.

the code i posted was part of a function called dropper_admin_page();

in that function i was calling another function containing all the variables, the function name was spelt wrong.

Wow i feel embarrased now.....It's amazing how the simplist things are the answer.

Although it won't have worked anyway without your help guys,

Thank you so so much