jQuery - checkbox enable/disable

Question

Change your markup slightly:

$(function() {
  enable_cb();
  $("#group1").click(enable_cb);
});

function enable_cb() {
  if (this.checked) {
    $("input.group1").removeAttr("disabled");
  } else {
    $("input.group1").attr("disabled", true);
  }
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<form name="frmChkForm" id="frmChkForm">
  <input type="checkbox" name="chkcc9" id="group1">Check Me <br>
  <input type="checkbox" name="chk9[120]" class="group1"><br>
  <input type="checkbox" name="chk9[140]" class="group1"><br>
  <input type="checkbox" name="chk9[150]" class="group1"><br>
</form>

You can do this using attribute selectors without introducing the ID and classes but it's slower and (imho) harder to read.

This is the most up-to-date solution.

<form name="frmChkForm" id="frmChkForm">
    <input type="checkbox" name="chkcc9" id="group1" />Check Me
    <input type="checkbox" name="chk9[120]" class="group1" />
    <input type="checkbox" name="chk9[140]" class="group1" />
    <input type="checkbox" name="chk9[150]" class="group1" />
</form>

$(function() {
    enable_cb();
    $("#group1").click(enable_cb);
});

function enable_cb() {
    $("input.group1").prop("disabled", !this.checked);
}

---

Here is the usage details for .attr() and .prop().

jQuery 1.6+

Use the new .prop() function:

$("input.group1").prop("disabled", true);
$("input.group1").prop("disabled", false);

jQuery 1.5 and below

The .prop() function is not available, so you need to use .attr().

To disable the checkbox (by setting the value of the disabled attribute) do

$("input.group1").attr('disabled','disabled');

and for enabling (by removing the attribute entirely) do

$("input.group1").removeAttr('disabled');

Any version of jQuery

If you're working with just one element, it will always be fastest to use DOMElement.disabled = true. The benefit to using the .prop() and .attr() functions is that they will operate on all matched elements.

// Assuming an event handler on a checkbox
if (this.disabled)

ref: Setting "checked" for a checkbox with jQuery?

<form name="frmChkForm" id="frmChkForm">
<input type="checkbox" name="chkcc9" id="chkAll">Check Me
<input type="checkbox" name="chk9[120]" class="chkGroup">
<input type="checkbox" name="chk9[140]" class="chkGroup">
<input type="checkbox" name="chk9[150]" class="chkGroup">
</form>

$("#chkAll").click(function() {
   $(".chkGroup").attr("checked", this.checked);
});

With added functionality to ensure the check all checkbox gets checked/dechecked if all individual checkboxes are checked:

$(".chkGroup").click(function() {
  $("#chkAll")[0].checked = $(".chkGroup:checked").length == $(".chkGroup").length;
});

Here's another sample using JQuery 1.10.2

$(".chkcc9").on('click', function() {
            $(this)
            .parents('table')
            .find('.group1') 
            .prop('checked', $(this).is(':checked')); 
});

$(document).ready(function() {
  $('#InventoryMasterError').click(function(event) { //on click
    if (this.checked) { // check select status
      $('.checkerror').each(function() { //loop through each checkbox
        $('#selecctall').attr('disabled', 'disabled');
      });
    } else {
      $('.checkerror').each(function() { //loop through each checkbox
        $('#selecctall').removeAttr('disabled', 'disabled');
      });
    }
  });

});

$(document).ready(function() {
  $('#selecctall').click(function(event) { //on click
    if (this.checked) { // check select status
      $('.checkbox1').each(function() { //loop through each checkbox
        $('#InventoryMasterError').attr('disabled', 'disabled');
      });

    } else {
      $('.checkbox1').each(function() { //loop through each checkbox
        $('#InventoryMasterError').removeAttr('disabled', 'disabled');
      });
    }
  });
});

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<input type="checkbox" id="selecctall" name="selecctall" value="All" />
<input type="checkbox" name="data[InventoryMaster][error]" label="" value="error" id="InventoryMasterError" />
<input type="checkbox" name="checkid[]" class="checkbox1" value="1" id="InventoryMasterId" />
<input type="checkbox" name="checkid[]" class="checkbox1" value="2" id="InventoryMasterId" />