jQuery Traversal - prevAll() Method
Example
Locate all divs before the last div and add the class to them:
$("div:last").prevAll().addClass("before");
Definition and Usage
prevAll() gets the preceding sibling elements of each element in the current matched element set, and using a selector for filtering is optional.
Syntax
.prevAll(selector)
| Parameter | Description |
|---|---|
| selector | String value, containing the selector expression used to match elements. |
Detailed Explanation
If a jQuery object representing a set of DOM elements is given, the .prevAll() method allows us to search for the preceding sibling elements of these elements in the DOM tree and construct a new jQuery object with matching elements.
This method accepts an optional selector expression, which is the same type of parameter as the one we pass to the $() function. If this selector is applied, it will filter the elements by checking whether the elements match the selector.
Think about this page with a basic nested list:
<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 start from the third item, we can find the sibling elements between the elements:
$('li.third-item').prevAll().css('background-color', 'red');
The result of the call here is to set the background color of item 2 and item 1 to red. Since we did not apply a selector expression, these preceding elements naturally become part of the object. If a selector has been applied, it will check whether these elements match the selector before including the elements.
