how do i find if ul contains li with id in an if condition

Question

how do i find if ul contains li with id 'liSubTask1' exists or not in an if condition in jquery

 <ul id='ulTask'>
   <li id='liSubTask1'>subTask1</li>
   <li id='liSubTask2'>subTask2</li>
   <li id='liSubTask3'>subTask3</li>
   <li id='liSubTask4'>subTask4</li>
   <li id='liSubTask5'>subTask5</li>
 </ul>

i wanted to find out if "li with id" exists in ul then do some thing

Answer 1

if($("#ulTask #liSubTask1").length)
{
   //your code here
}

Answer 2

The ">" symbol restricts a selector to direct descendents of the first selector: http://api.jquery.com/child-selector/

if ($('#ulTask > li#liSubTask4').length) {
   //...
}

Answer 3

this sounds very familiar to these questions "Is there an “exists” function for jQuery" and "How do you check if a selector exists in jQuery?"

jQuery.fn.exists = function(){return this.length>0;}

if ($(selector).exists()) {
    // Do something
}

Answer 4

if($('ul#ulTask li#liSubTask1').length) {
   // do stuff
}

Answer 5

var nextli = $("#ulTask").next(li);
var id = nextli.attr('id');

Answer 6

use the following code if you want to check all the inner child elements too..

if($('#ulId').find('#liId').length > 0)