$ (obj). The difference between index (this) and (this). Index ()

<div id= "NAV" >
<p>111111</p>
<p>222222</p>
<b>333333</b>
<b>444444</b>
</div>

JavaScript section introduces JavaScript first

<script>

$ (obj). Index (this) selects the subscript based on the object; index () is based on the subscript of all elements of this sibling;

$ ("B"). Click (function () {

var num = $ ("B"). index (this);

var index = $ (this). index ();

alert (num);

alert (Index);

Then the first pop-up 0 and then pop 2, click the last B first pop 1 and then pop 3;

});

</script>

$ (obj). The difference between index (this) and (this). Index ()