Jquery operates on several methods of the checked and disabled properties

2020-03-30 03:24:49
OfStack

There is no difference between the following two methods except that there is less code...



<input id="cb1" type="checkbox" checked />

<input id="cb2" type="checkbox" checked="checked" />

Jquery determines checked in three ways:



.attr('checked'):   //See version 1.6+ return :"checked" or "undefined"; 1.5- returns :true or false

.prop('checked'): //16+:true/false

.is(':checked'):    // All versions :true/false// Don't forget the colon

Several ways to write jquery checked:

All jquery versions can be assigned like this:



$("#cb1").attr("checked","checked");

$("#cb1").attr("checked",true);

Jquery1.6 +: 4 assignments for prop:



$("#cb1").prop("checked",true);    //It's easy to forget 

$("#cb1").prop({checked:true});    //The map key/value pair
$("#cb1").prop("checked",function(){

    return true;    //The function returns true or false

});
$("#cb1").prop("checked","checked");

More reference: http://api.jquery.com/prop/



<html>

    <head>

        <title> test </title>

        <style type="text/css">
        </style>

        <!--1.62 You can modify 1.42  1.52  1.7 To test the -->

        <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.6.2/jquery.min.js"></script>

        <script type="text/javascript">

        $(function(){

            //Judge checked < br / >
　　　　　　 //    var a=$("#cb1").attr('checked'); // See the version 1.6+ return :"checked" or "undefined" ;1.5- return :true or false

　　　　　　 //    var b=$("#cb1").prop('checked'); //1.6+:true/false

　　　　　　 var c=$("#cb1").is(':checked');  //All versions :true/false

　　　　　　 //    alert(a);        

　　　　　 　//    alert(b);

            alert(c);

           //Assignment     All of the first two jquery versions support prop except for query1.6+, which supports 

　　　　　　 //    $("#cb1").attr("checked","checked");//1.5-

　　　　　　 //    $("#cb1").attr("checked",true);//1.5-

　　　　　　　//　　　$("#cb1").prop("checked","checked");//1.6+( I forgot this when I was tidying up )

　　　　　　 //    $("#cb1").prop("checked",true);//1.6+

　　　　　　 //    $("#cb1").prop({checked:true});//1.6+

 　　　　　　//    $("#cb1").prop("checked",function(){

　　　　　　 //        return  true;//1.6+

　　　　　　 //    });                

        })();

    

        </script>

    </head>

    <body>

        <!-- Remember to get rid of it when you assign checked-->

    <input id="cb1" type="checkbox" checked />

    <input id="cb2" type="checkbox" checked="checked"/>

    </body>

</html>