Categories

.prevAll()

Categories: Tree Traversal

.prevAll( [ selector ] )Returns: jQuery

Description: Get all preceding siblings of each element in the set of matched elements, optionally filtered by a selector.

  • .prevAll( [ selector ] )

    version added: 1.0

    selector   A string containing a selector expression to match elements against.

Given a jQuery object that represents a set of DOM elements, the .prevAll() method searches through the predecessors of these elements in the DOM tree and construct a new jQuery object from the matching elements; the elements are returned in order beginning with the closest sibling.

The method optionally accepts a selector expression of the same type that we can pass to the $() function. If the selector is supplied, the elements will be filtered by testing whether they match it.

Consider a page with a simple list on it:

<ul>
   <li>list item 1</li>
   <li>list item 2</li>
   <li class="third-item">list item 3</li>
   <li>list item 4</li>
   <li>list item 5</li>
</ul>

If we begin at the third item, we can find the elements which come before it:

$('li.third-item').prevAll().css('background-color', 'red');

The result of this call is a red background behind items 1 and 2. Since we do not supply a selector expression, these preceding elements are unequivocally included as part of the object. If we had supplied one, the elements would be tested for a match before they were included.

  • Locate all the divs preceding the last div and give them a class.

    HTML:
    <div></div>
      <div></div>
      <div></div>
      <div></div>
    CSS:
    
    
      div { width:70px; height:70px; background:#abc; 
            border:2px solid black; margin:10px; float:left; }
      div.before { border-color: red; }
      
    Code:
    $("div:last").prevAll().addClass("before");