CODEWITHSUNDEEP
phpcheckboxfor-loop
user860511
user860511

Reputation:

PHP Loop for Checked Boxes is returning errors

I am currently trying to design a for loop to iterate through any 'checked' check boxes, and from that, use the value within the 'value' slot to run some queries. I am unfortunately struggling with this as the list of checkboxes are not pre-defined, they are dynamic from the database pending the users previous selection.

The loop actually works to present the items to be checked:

?>
    <input type="checkbox" name="option[]" value="$listing_id">
    <font size="+1" color="green"><?php echo"$list_name"; ?>:</font><br />
<?php

The listing ID within the value is what I need to work with in a mysql query before I run an update query. The for loop that's meant to work is:

foreach($_POST['option'] as $option) //loop through the checkboxes
{
    ...
}

The update query will work within this as its simply copied from somewhere else, I just need the 'Listing_ID' from the check boxes that are checked.

I ran this code to hopefully do some debugging:

if(empty($_POST['option'])){
    echo "no checkboxes checked.";
} else {
    if(!isset($_POST['option'])){
        echo "no set.";
    }
}

and it returns "no checkboxes checked."

I have now hit a grey area as to why this for loop isn't working (this was taken from another example on the internet).

Upvotes: 1

Views: 719

Answers (3)

brenjt
brenjt

Reputation: 16297

Try echoing out the $option in the loop to see what the value is and there you can see if there is something there.

foreach($_POST['option'] as $option) //loop through the checkboxes
{
    echo $option . "<br />";
}

Also make sure your form's method is set to POST or that it's action is pointed to the correct place. You also have an error in your input:

<input type="checkbox" name="option[]" value="$listing_id">

I assume you meant:

<input type="checkbox" name="option[]" value="<?php echo $listing_id;?>">

UPDATE:

The error ended up not being in the code posted. Error was discovered in an if statement that always returned false that in-cased the code posted above.

Upvotes: 0

Gianpaolo Di Nino
Gianpaolo Di Nino

Reputation: 1147

First of all your code seems to be bugged to me. Maybe is just a typo but 

 <input type="checkbox" name="option[]" value="$listing_id">

should be

 <input type="checkbox" name="option[]" value="<?=$listing_id?>"/>

Moreover using empty over an array is not good at all.

Upvotes: 1

hakre
hakre

Reputation: 198219

empty($_POST['option']) will return true, if either $_POST['option'] is not set (same as !isset($_POST['option']) (!)) or an empty array.

If you need to debug what's going on, use var_dump($_POST['option']); to find out what has been submitted for the option checkboxes. I also suggest you do a var_dump($_POST); so you can see what has been submitted overall - e.g. in case the post action is not post you will immediatly notice). For HTML output:

echo '<pre>', htmlspecialchars(print_r($_POST, true)), '</pre>';

That should give you the information you're looking for. For each individual checkbox, you can do:

foreach($_POST['option'] as $option) //loop through the checkboxes
{
    var_dump($option);
}

Upvotes: 1

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