How to know if a checkbox is checked

Question

I'm trying to test if a checkbox is checked or no I found this solution but I'm getting nothing

if(document.getElementById('checkbox-1').checked) {
  alert("checked");
}

<input id="checkbox-1" class="checkbox-custom" name="checkbox-1" type="checkbox">

Duplicate http://stackoverflow.com/questions/2204250/check-if-checkbox-is-checked-with-jquery — ProgrammerV5, Apr 18 '17 at 18:51
Possible duplicate of [Check if checkbox is checked with jQuery](http://stackoverflow.com/questions/2204250/check-if-checkbox-is-checked-with-jquery) — ProgrammerV5, Apr 18 '17 at 18:52
there isn't really any 'event' to trigger that JavaScript. Maybe that should happen when the checkbox is checked or not? on 'change' maybe? — sheriffderek, Apr 18 '17 at 18:52
The OP doesn't actually ask for event capturing, just how to test the checked state — JSDBroughton, Apr 18 '17 at 18:59
@SamJones the question has the jquery tag in it hence the suggestion. — ProgrammerV5, Apr 19 '17 at 14:26

Anant Kumar Singh · Accepted Answer · 2017-04-18T19:03:21.440

1

You have to trigger click even of check-box which will call a function that do the desired task.

Example how you can do it:-

function checkClick(){
  if(document.getElementById('checkbox-1').checked) {
    alert("checked");
  }
}

<input id="checkbox-1" class="checkbox-custom" name="checkbox-1" type="checkbox" onclick="checkClick()"> <!-- trigger click event using onclick and calling a function -->

Note:- you can change function name according to your wish.

edited Apr 18 '17 at 19:03

answered Apr 18 '17 at 18:54

Anant Kumar Singh

68,309
10
50
94

4

In the modern era, we should not be encouraging the use of inline event handlers. Also, this question is a duplicate of many, many others. – Heretic Monkey Apr 18 '17 at 19:01
@Amal glad to help you. :):) – Anant Kumar Singh Apr 18 '17 at 19:03
It depends how the Inline event handlers are being used. For learning it's ok to use this code. Also, in this question OP said that it didn't work. That means the OP is asking about why the alert didn't work. – Abhinav Galodha Apr 18 '17 at 19:06

score 0 · Answer 2 · answered Apr 18 '17 at 18:57

You need to Trigger the event. For checkbox, the onchange event would fire anytime the value changes. So, you need to hook up a event handler which can be a function reference or function declaration like onchange="checkboxChanged()

function checkboxChanged(){
if(document.getElementById('checkbox-1').checked) {
    alert('checked');
  }
    else{
      alert('Not checked');
    }
}

<input id="checkbox-1" class="checkbox-custom" name="checkbox-1" type="checkbox" onchange="checkboxChanged()"/>

How to know if a checkbox is checked

2 Answers2