Check/Uncheck checkbox with JavaScript (jQuery or vanilla)?

Question

How can a checkbox be checked/unchecked using JavaScript, jQuery or vanilla?

Answer 1

to check:

document.getElementById("id-of-checkbox").checked = true;

to uncheck:

document.getElementById("id-of-checkbox").checked = false;

Answer 2

If, for some reason, you don't want to (or can't) run a .click() on the checkbox element, you can simply change its value directly via its .checked property (an IDL attribute of <input type="checkbox">).

Note that doing so does not fire the normally related event (change) so you'll need to manually fire it to have a complete solution that works with any related event handlers.

Here's a functional example in raw javascript (ES6):

class ButtonCheck {
  constructor() {
    let ourCheckBox = null;
    this.ourCheckBox = document.querySelector('#checkboxID');

    let checkBoxButton = null;
    this.checkBoxButton = document.querySelector('#checkboxID+button[aria-label="checkboxID"]');

    let checkEvent = new Event('change');
    
    this.checkBoxButton.addEventListener('click', function() {
      let checkBox = this.ourCheckBox;

      //toggle the checkbox: invert its state!
      checkBox.checked = !checkBox.checked;

      //let other things know the checkbox changed
      checkBox.dispatchEvent(checkEvent);
    }.bind(this), true);

    this.eventHandler = function(e) {
      document.querySelector('.checkboxfeedback').insertAdjacentHTML('beforeend', '<br />Event occurred on checkbox! Type: ' + e.type + ' checkbox state now: ' + this.ourCheckBox.checked);

    }


    //demonstration: we will see change events regardless of whether the checkbox is clicked or the button

    this.ourCheckBox.addEventListener('change', function(e) {
      this.eventHandler(e);
    }.bind(this), true);

    //demonstration: if we bind a click handler only to the checkbox, we only see clicks from the checkbox

    this.ourCheckBox.addEventListener('click', function(e) {
      this.eventHandler(e);
    }.bind(this), true);


  }
}

var init = function() {
  const checkIt = new ButtonCheck();
}

if (document.readyState != 'loading') {
  init;
} else {
  document.addEventListener('DOMContentLoaded', init);
}

<input type="checkbox" id="checkboxID" />

<button aria-label="checkboxID">Change the checkbox!</button>

<div class="checkboxfeedback">No changes yet!</div>

If you run this and click on both the checkbox and the button you should get a sense of how this works.

Note that I used document.querySelector for brevity/simplicity, but this could easily be built out to either have a given ID passed to the constructor, or it could apply to all buttons that act as aria-labels for a checkbox (note that I didn't bother setting an id on the button and giving the checkbox an aria-labelledby, which should be done if using this method) or any number of other ways to expand this. The last two addEventListeners are just to demo how it works.

Answer 3

For single check try

myCheckBox.checked=1

<input type="checkbox" id="myCheckBox"> Call to her

for multi try

document.querySelectorAll('.imChecked').forEach(c=> c.checked=1)

Buy wine: <input type="checkbox" class="imChecked"><br>
Play smooth-jazz music: <input type="checkbox"><br>
Shave: <input type="checkbox" class="imChecked"><br>

Answer 4

Javascript:

// Check
document.getElementById("checkbox").checked = true;

// Uncheck
document.getElementById("checkbox").checked = false;

jQuery (1.6+):

// Check
$("#checkbox").prop("checked", true);

// Uncheck
$("#checkbox").prop("checked", false);

jQuery (1.5-):

// Check
$("#checkbox").attr("checked", true);

// Uncheck
$("#checkbox").attr("checked", false);

Answer 5

I agree with the current answers, but in my case it does not work, I hope this code help someone in the future:

// check
$('#checkbox_id').click()

Answer 6

vanilla (PHP) will check box on and off and store result.

<?php
    if($serverVariable=="checked") 
        $checked = "checked";
    else
        $checked = "";
?>
<input type="checkbox"  name="deadline" value="yes" <?= $checked 
?> >

# on server
<?php
        if(isset($_POST['deadline']) and
             $_POST['deadline']=='yes')
             $serverVariable = checked;    
        else
             $serverVariable = "";  
?>