.has()
Reduce the set of matched elements to those that have a descendant that matches the selector or DOM element.
.has(selector)🡢 jQuery
selector
| String | A string containing a selector expression to match elements against. |
.has(contained)🡢 jQuery
contained
| Element | A DOM element to match elements against. |
Given a jQuery object that represents a set of DOM elements, the .has() method constructs a new jQuery object from a subset of the matching elements. The supplied selector is tested against the descendants of the matching elements; the element will be included in the result if any of its descendant elements matches the selector.
Consider a page with a nested list as follows:
<ul>
<li>list item 1</li>
<li>
list item 2
<ul>
<li>list item 2-a</li>
<li>list item 2-b</li>
</ul>
</li>
<li>list item 3</li>
<li>list item 4</li>
</ul>
We can apply this method to the set of list items as follows:
$("li").has("ul").css("background-color", "red");
The result of this call is a red background for item 2, as it is the only <li> that has a <ul> among its descendants.
Check if an element is inside another.
JS
<ul>
<li>Does the UL contain an LI?</li>
</ul>
CSS
.full {
border: 1px solid red;
}
HTML
$("ul").append("<li>" + ($("ul").has("li").length ? "Yes" : "No") + "</li>");
$("ul").has("li").addClass("full");
DEMO