Question

I have an array of checkboxes name=”box[]”. Through PHP I make sure that they’re checked after they’re submitted by echoing “checked=’checked'” if they were checked at submit event.

Now, if I check the third box, the value jumps down to the first checkbox after submit, since the array was empty up until the third checkbox. Same, if I check the 2nd and 3rd checkbox, they jump down to 1st and 2nd after submit. This is the code I’m using:

<form method="post">
    <input type="checkbox" name="box[]" value="true" <?php if ($box[0] == true) echo "checked='checked'"; ?>><br>
    <input type="checkbox" name="box[]" value="true" <?php if ($box[1] == true) echo "checked='checked'"; ?>><br>
    <input type="checkbox" name="box[]" value="true" <?php if ($box[2] == true) echo "checked='checked'"; ?>><br>
    <p>
    <input type="submit" value="Submit">
</form>

Try it at:
http://experiencerapanui.com/selecttest.php

Can I make the checkboxes fill up the array with a value “false” or whatever, if the box is unchecked? Which way should I go?

****** EDIT ******

Thanks to phant0m, I managed to come up with a solution:

<form method="post">
    <input type="checkbox" name="box[]" value="1" <?php if (in_array("1", $box)) echo "checked='checked'"; ?>><br>
    <input type="checkbox" name="box[]" value="2" <?php if (in_array("2", $box)) echo "checked='checked'"; ?>><br>
    <input type="checkbox" name="box[]" value="3" <?php if (in_array("3", $box)) echo "checked='checked'"; ?>><br>
    <p>
    <input type="submit" value="Submit">
</form>

Putting unique values for the checkboxes, then if I find the value in the array $box[], the box is marked as checked.

Answer 1

This does not work, because only those checkboxes, that are checked, are being put into the $box array.

Either use different names, or different values to distinguish between them.

Consider this: You check the second and the third checkbox. In PHP, you will receive:

$_POST['box'] = array(0 => "true", 1 => "true");

You cannot know, which checkboxes have been checked, unless all of them are.