Selecting multiple check boxes in a group using jQuery

var arr = ['1','3','8'];
/* find all the checkbox input elements.
   set the 'checked' property */
$('input[type=checkbox]').prop('checked', function(){
    // return  true if the value is in the array, false if not
    return $.inArray(this.value, arr) > -1;
});

JS Fiddle demo.

Or, using filter():

var arr = ['1','3','8'];

$('input[type=checkbox]').filter(function(){
    return $.inArray(this.value, arr) > -1;
}).prop('checked',true);

JS Fiddle demo.

It might be worth, however, first unchecking any already-checked checkboxes before you set the property:

var arr = ['1','3','8'];

$('input[type=checkbox]').prop('checked',false).filter(function(){
    return $.inArray(this.value, arr) > -1;
}).prop('checked',true);

JS Fiddle demo.

Finally, because the value of an input is always a string, whereas numbers in JavaScript don't have to be quoted, to allow for unquoted numbers in the array (to guard against forgetfulness, if nothing else):

var arr = ['1',3,'8'];

$('input[type=checkbox]').prop('checked',false).filter(function(){
    return $.inArray(this.value, arr.toString()) > -1;
}).prop('checked',true);

JS Fiddle demo.

References:

• filter().
• jQuery.inArray()
• prop()
• toString().

By example, for the value 8 :

<input type="checkbox" class="chk" name="myGroup[]" value="7" />
<input type="checkbox" class="chk" name="myGroup[]" value="8" />

<script>
  $(".chk[value='8']").prop("checked", true);
</script>

This is one way to do it - give your checkboxes a common class, i.e. "myCheckbox".

Use jQuery to iterate through all the checkboxes with the class "myCheckbox", and compare their value with the list provided by the user. If there's a match, select the checkbox.

Pseudo jQuery code:

$('.myCheckbox').each(function() {
  // you would search the array here
  if ($(this).value == "1") {
    $(this).check();
  }
});

You can try this -

var arr =  ["1","3","8"];
$(':checkbox').each(function(){
  if($.inArray(this.value,arr) > -1){
   $(this).prop('checked',true);
  }
}) 

This should fix your issue:

var setArr = ["1","3","8"];

$('.checkbox').each(function(i, j){
if(jQuery.inArray($(j).val(), setArr)!= -1){

$(j).attr('checked', 'checked');
}

});

FIDDLE