Use .prop() to get or set the dynamic, changing, visual state of a checkbox.

http://jquery.com/upgrade-guide/1.9/#attr-versus-prop-

#13334 is a duplicate of this ticket.

#13358 is a duplicate of this ticket.

#13345 is a duplicate of this ticket.

#13369 is a duplicate of this ticket.

#13454 is a duplicate of this ticket.

#13500 is a duplicate of this ticket.

#13519 is a duplicate of this ticket.

#13573 is a duplicate of this ticket.

#13833 is a duplicate of this ticket.

#13845 is a duplicate of this ticket.

#13863 is a duplicate of this ticket.

#13876 is a duplicate of this ticket.

#13895 is a duplicate of this ticket.

#13920 is a duplicate of this ticket.

#13958 is a duplicate of this ticket.

#13979 is a duplicate of this ticket.

#14112 is a duplicate of this ticket.

#14437 is a duplicate of this ticket.

#14518 is a duplicate of this ticket.

#14501 is a duplicate of this ticket.

#14539 is a duplicate of this ticket.

#14571 is a duplicate of this ticket.

#14602 is a duplicate of this ticket.

HTML:

<div id="sample">
    <input type="checkbox"> 
    <input type="checkbox"> 
    <input type="checkbox">
<div>
<input id="checkAll" type="checkbox">

JQuery

$("#checkAll").click(function() {
    
    var checked = $(this).is(":checked");
    
    // hack
    $("div#sample input[type=checkbox]").each(function() {
        $(this)[0].checked = checked;
    });
    
});

#14651 is a duplicate of this ticket.

#14774 is a duplicate of this ticket.

#15152 is a duplicate of this ticket.