Looping through Checkboxes using Javascript

Question

I tried using javascript samples that I found here and other places. The problem is that I am using a Table control working at the server, so the javascript I was using does not

Answer 1

You need something like this

var pass = true;

for (var i = 0; i < form.elements.length; i++ ) 
{
    if (form.elements[i].type == 'checkbox')
    {
        if (form.elements[i].checked == false)
        {
            pass = false;
        }
    }
}

if(!pass)
{
    alert ('You must check all the checkboxes!');
}

return pass;

Hope this helps.

Answer 2

You can get the HTML ID of the checkboxes by using the C# ClientID property. Insert that ID into your Javascript, and you will then be able to select the relevant checkboxes and do whatever you like with them.

Answer 3

Use querySelectorAll to check for any unchecked check boxes. If there are any, throw the error message, else postback.

function checkCheckboxes(){
   if(document.querySelectorAll('input[type="checkbox"]:not(:checked)').length > 0){
     alert("all checkboxes must be checked");
     return false;
   } else{
     return true;
   }
}

Note: this will only work in Modern browsers Firefox 3.1+, IE8+ (only in IE8 standards mode), and Safari 3.1+