Trying to set default checkbox value if not checked

Question

Basically I can get the value that applies to when the box is ticked (= 1), but I can't get it to send the default value of 0 when not checked.

<input type="checkbox" name="post_friend" value="1">

I've searched around and someone suggested setting a hidden checkbox, but it's not working for me.

<input type="hidden" name="post_friend" value="0">

Yes I put the hidden field BEFORE the unhidden value, it's tagged mysql/php because I am inserting into a mysql database(value 1) and wasn't sure if there was a PHP trick to get this working. — user2571547, Jul 17 '13 at 00:08
Duplicate question: http://stackoverflow.com/questions/1809494/post-the-checkboxes-that-are-unchecked — dispake, Jul 17 '13 at 00:08

score 5 · Accepted Answer · answered Jul 17 '13 at 00:08

5

Could you not do something like this?

$checkbox = isset($_POST['post_friend']) ? $_POST['post_friend'] : 0 ;

So if the checkbox is checked, variable is 1. If not, variable assigned value of 0

answered Jul 17 '13 at 00:08

Becs Carter

1,250
1
12
27

the problem with this, is that you may not know the names of the unchecked fields. I have a similar problem, on which, depending on user data, the checkboxes' id's can vary. I can know what checkboxes (their id's) are checked after submission, but i cannot know (directly) what other checkboxes were there and were unchecked, so i could not update them on DB. – DiegoDD Dec 30 '13 at 18:55

score 1 · Answer 2 · answered May 14 '14 at 12:01

The original method which was given by the OP should work, however, the value may very well be different.

For example,

<input type="checkbox" name="post_friend" value="1">
<input type="hidden" name="post_friend" value="0">

In this case ["post_friend"] = 0.

However, in this example:

<input type="checkbox" checked="checked" name="post_friend" value="1">
<input type="hidden" name="post_friend" value="0">

Most browsers will send ["post_friend"] = "1,0". Multiple values to the same property will usually be concatenated in the http request.

For this you can use String.Contains to find the 1.

However, here, you should really assess whether your input should be a checkbox, or more suitably, radio input.

score 0 · Answer 3 · answered Nov 22 '13 at 13:27

Try something like below

<div class="col-xs-5 drinkingLeft">
<input type="checkbox" name="beer" id="beer"class="require-one col-xs-1" value="0"/>
<input id='beerHidden'  type='hidden' value='0' name='beer'>   
<label for="beer" class="col-xs-10">Beer </label>
</div>


 $('#beer').on('change', function () {
this.value = this.checked ? 1 : 0;
 }).change();

$("#submit").click(function () {
if(document.getElementById("beer").checked){
document.getElementById('beerHidden').disabled = true;
}
});

score 0 · Answer 4 · answered Jan 09 '17 at 10:33

0

HTML

 <input type="checkbox" id="chkbox1">

Jquery

if( $("#chkbox1").is(':checked')){
            value = "True";
        }else{
            value= "False";
        }

answered Jan 09 '17 at 10:33

Aravindh Gopi

2,083
28
36

score 0 · Answer 5 · answered Jul 21 '19 at 10:53

the only possible solution is :

<?php
    // if data is posted, set value to 1, else to 0
    $check_0 = isset($_POST['check'][0]) ? 1 : 0;
    $check_1 = isset($_POST['check'][1]) ? 1 : 0;
?>

If you want to check info on the same page then use JS and check NULL values...

Trying to set default checkbox value if not checked

5 Answers5

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