.find()
Categories: Tree Traversal
.find( selector )Returns: jQuery
Description: Get the descendants of each element in the current set of matched elements, filtered by a selector, jQuery object, or element.
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.find( selector )
version added: 1.0selector A string containing a selector expression to match elements against.
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.find( jQuery object )
version added: 1.0jQuery object A jQuery object to match elements against.
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.find( element )
version added: 1.0element An element to match elements against.
Given a jQuery object that represents a set of DOM elements, the .find()
method allows us to search through the descendants of these elements in the DOM tree and construct a new jQuery object from the matching elements. The .find()
and .children()
methods are similar, except that the latter only travels a single level down the DOM tree.
The first signature for the .find()
method accepts a selector expression of the same type that we can pass to the $()
function. The elements will be filtered by testing whether they match this selector.
Consider a page with a basic nested list on it:
<ul class="level-1"> <li class="item-i">I</li> <li class="item-ii">II <ul class="level-2"> <li class="item-a">A</li> <li class="item-b">B <ul class="level-3"> <li class="item-1">1</li> <li class="item-2">2</li> <li class="item-3">3</li> </ul> </li> <li class="item-c">C</li> </ul> </li> <li class="item-iii">III</li> </ul>
If we begin at item II, we can find list items within it:
$('li.item-ii').find('li').css('background-color', 'red');
The result of this call is a red background on items A, B, 1, 2, 3, and C. Even though item II matches the selector expression, it is not included in the results; only descendants are considered candidates for the match.
Unlike in the rest of the tree traversal methods, the selector expression is required in a call to
.find()
. If we need to retrieve all of the descendant elements, we can pass in the universal selector'*'
to accomplish this.
Selector context is implemented with the .find()
method;
therefore, $('li.item-ii').find('li')
is equivalent to $('li', 'li.item-ii')
.
As of jQuery 1.6, we can also filter the selection with a given jQuery collection or element. With the same nested list as above, if we start with:
var $allListElements = $('li');
And then pass this jQuery object to find:
$('li.item-ii').find( $allListElements );
This will return a jQuery collection which contains only the list elements that are descendants of item II.
Similarly, an element may also be passed to find:
var item1 = $('li.item-1')[0]; $('li.item-ii').find( item1 ).css('background-color', 'red');
The result of this call would be a red background on item 1.
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Starts with all paragraphs and searches for descendant span elements, same as $("p span")
HTML:
<p><span>Hello</span>, how are you?</p> <p>Me? I'm <span>good</span>.</p>
Code:
$("p").find("span").css('color','red');
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A selection using a jQuery collection of all span tags. Only spans within p tags are changed to red while others are left blue.
HTML:
<p><span>Hello</span>, how are you?</p> <p>Me? I'm <span>good</span>.</p> <div>Did you <span>eat</span> yet?</div>
CSS:
span { color: blue; }
Code:
var $spans = $('span'); $("p").find( $spans ).css('color','red');
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Add spans around each word then add a hover and italicize words with the letter t.
HTML:
<p> When the day is short find that which matters to you or stop believing </p>
CSS:
p { font-size:20px; width:200px; cursor:default; color:blue; font-weight:bold; margin:0 10px; } .hilite { background:yellow; }
Code:
var newText = $("p").text().split(" ").join("</span> <span>"); newText = "<span>" + newText + "</span>"; $("p").html( newText ) .find('span') .hover(function() { $(this).addClass("hilite"); }, function() { $(this).removeClass("hilite"); }) .end() .find(":contains('t')") .css({"font-style":"italic", "font-weight":"bolder"});