选中/取消选中所有复选框，单击一个复选框javascript

Question

I have a form in which I have two table with some rows .

I want that when I click on select/unselect all check box than checkboxes under the that check box should checked for that particular table

I have a javascript function that works but when I click any of two select/unselect all checkbox than both tables checkboxes are checked. I want to check all checkboxes for the particular table only.

Javascript:

<script type="text/javascript">
checked=false;
function checkedAll (frm1) {
    var aa= document.getElementById('frm1');
     if (checked == false)
          {
           checked = true
          }
        else
          {
          checked = false
          }
    for (var i =0; i < aa.elements.length; i++) 
    {
     aa.elements[i].checked = checked;
    }
      }

      //function for subscription month


</script>

my html is....

<form action="" method="post" name="frm1" id="frm1">

<table>
<tr><th>Cause List</th></tr>
<?php 
foreach($arr as $month)
{
?>
<tr><td><input type="checkbox" name="causelist_month" /><?php echo $month; ?></td></tr>
<?php } ?>
<tr><th><input type="checkbox" name="causelist_month" id="causelist_month" onclick="checkedAll (frm1);"/>select all/unselect all</th></tr>
</table>
<table>
<tr><th>Subscription</th></tr>
<?php 
foreach($arr as $month)
{
?>
<tr><td><input type="checkbox" name="subscription_month"/><?php echo $month; ?></td></tr>
<?php } ?>
<tr><th><input type="checkbox" name="subscription_month" id="subscription_month" onclick="checkedAll2 (frm2);"/>select all/unselect all</th></tr>
</table>
</form>

please help me.

Answer 1

With jQuery 1.6+, you can do

$('.check-all').click(function () {
    var checked = this.prop('checked');   
    this.closest('table').find(':checkbox').prop('checked', checked);
}

where check-all is a class that the two "select/unselect all" checkboxes have.

Answer 2

There are a couple of problems with your code. The most important one is that you are aa single checked variable to keep track of the state for both forms. That cannot work. Instead, use the status of the "checkall" checkbox for the other checkboxes.

Lets assume you really have two forms (if you cannot use two forms, see below):

<form action="" method="post" name="frm1" id="frm1">
    <table>    
        <tr><th>Cause List</th></tr>
        <!-- ... -->
        <tr>
            <th>
                <input type="checkbox" name="causelist_month" id="causelist_month" onclick="checkedAll.call(this);"/>select all/unselect all
            </th>
        </tr>  
    </table>
</form>

<form action="" method="post" name="frm2" id="frm2">
    <table>    
        <tr><th>Subscription List</th></tr>
        <!-- ... -->
        <tr>
            <th>
                <input type="checkbox" name="subscription_month" id="subscription_month" onclick="checkedAll.call(this);"/>select all/unselect all
            </th>
        </tr>  
    </table>
</form>

Note that I changed the inline event handler to checkedAll.call(this) .

Then your function should look like this:

function checkedAll() {
    // this refers to the clicked checkbox
    // find all checkboxes inside the checkbox' form
    var elements = this.form.getElementsByTagName('input');
    // iterate and change status
    for (var i = elements.length; i--; ) {
        if (elements[i].type == 'checkbox') {
            elements[i].checked = this.checked;
        }
    }
}

DEMO

Of course there are ways to improve the code. For example you probably want to add the logic to deselect the respective "select all" checkbox when any if the other checkboxes in the table is deselected.

I also recommend to read the great introduction to event handling on quirksmode.org , to learn about other ways of binding event handlers.

---

If you cannot use two forms, you have to find another ancestor as reference point (ie from which you select all the checkboxes). In this case, the table element seems preferable. You have to traverse up the document, until you find it. The inline click event handler still has to be changed to checkedAll.call(this) for this to work:

function checkedAll() {
    // this refers to the clicked checkbox

    // find closest table
    var parent = this.parentNode;
    do {
        parent = parent.parentNode;
    } while(parent.nodeName !== 'TABLE');

    // find all checkboxes inside the checkbox' table
    var elements = parent.getElementsByTagName('input');

    // ... continue like shown above
}

Answer 3

You code is changing all checkbox which are inside frm1 . Keep two tables inside two separate div's and pass corresponding divs id to checkedAll function .

<form action="" method="post" name="frm1" id="frm1"> 
<div id="div1">
<table>  
   <tr>
         <th>Cause List</th>
  </tr>
  <?php foreach($arr as $month) { ?> 
   <tr><td><input type="checkbox" name="causelist_month" />
   <?php echo $month; ?></td></tr> 
   <?php } ?> 
   <tr>
   <th>
    <input type="checkbox" name="causelist_month" id="causelist_month" onclick="checkedAll (div1);"/>select all/unselect all</th></tr> </table>  
   </div>
   <div id="div2">
   // Second table
   </div>  
  </form>

Answer 4

Try this --

$(input[type=checkbox]').attr('checked', 'checked');

HTML -

<div><label><input id="ChkAll" type="checkbox" onchange="javascript:CheckedAll();" /><span>SelectAll</span></label></div> 
 <div id="DivChk ">
    <label><input type="checkbox" /><span>First</span></label>
    <label><input type="checkbox" /><span>2nd</span></label>
    <label><input type="checkbox" /><span>3rd</span></label>
    <label><input type="checkbox" /><span>4th</span></label>
</div>

My Jquery -

function CheckedAll(){
     if ($('#ChkAll').is(':checked')) {
          $('#DivChk input[type=checkbox]').attr('checked', 'checked');           
     }
     else {
          $('#DivChk input[type=checkbox]:checked').removeAttr('checked');
     }
   }

Try This using Jquery

BY Javascript -

function CheckedAll(){    
     if (document.getElementById('ChkAll').checked) {
         for(i=0; i<document.getElementsByTagName('input').length;i++){
         document.getElementsByTagName('input')[i].checked = true;
         }
     }
     else {
         for(i=0; i<document.getElementsByTagName('input').length;i++){
          document.getElementsByTagName('input')[i].checked = false;
         }
     }
   }

Try This

Answer 5

Try this

function checkedAll(frm1) {
  var chk = document.getElementsByTagName('input');
  for(var i=0; i < chk.length; i++) {
    if(chk[i].type == 'checkbox') {
      chk[i].checked = frm1.checked;
    }
  }
}

or you can find more details here .

Answer 6

try this DEMO

var checked=false;
function checkedAll () {
var aa =  document.getElementsByName("causelist_month");
checked = document.getElementById('causelist_month').checked;

for (var i =0; i < aa.length; i++) 
{
    aa[i].checked = checked;
}
}

function checkedAll2() {
var aa =  document.getElementsByName("subscription_month");
checked = document.getElementById('subscription_month').checked;


for (var i =0; i < aa.length; i++) 
{
    aa[i].checked = checked;
}
}