jQuery andSelf: Purpose and Deprecation

This article provides a concise overview of jQuery's .andSelf() method, detailing its purpose in DOM traversal, the reasons for its deprecation in jQuery 1.8 and removal in jQuery 3.0, and the modern alternative developers should use in its place.

What is the jQuery andSelf() Method?

The .andSelf() method was a DOM traversal method in jQuery used to combine the previous set of matched elements on the internal stack with the current set of matched elements.

When you perform traversal operations in jQuery—such as .parent(), .children(), .find(), or .next()—jQuery creates a new collection representing the elements you navigated to, pushing the previous selection onto an internal stack. The .andSelf() method allowed developers to include the previous element set alongside the newly selected elements, making it possible to apply subsequent methods to both sets simultaneously.

Basic Syntax and Example

// Select all <ul> elements, find their <li> children, 
// and include the original <ul> elements in the matched set
$("ul").find("li").andSelf().addClass("highlight");

In this example, without .andSelf(), only the <li> elements would receive the highlight class. Calling .andSelf() merges the original <ul> elements back into the selection, applying the class to both the <ul> and <li> elements.

Why Was andSelf() Deprecated?

jQuery deprecated .andSelf() in version 1.8 and permanently removed it in version 3.0. The primary reason for its deprecation was poor naming semantics and limited functionality:

  1. Misleading Name: The term "self" implied that the method was specifically referring to an original or root element. However, in chained traversal calls, the previous item on the stack was simply whatever element set existed immediately before the last traversal step, not necessarily "itself."
  2. Lack of Filtering: The method automatically added back all elements from the previous stack frame with no way to filter them.

The Modern Alternative: .addBack()

To fix the naming ambiguity and add flexibility, jQuery replaced .andSelf() with .addBack().

The .addBack() method functions identically to .andSelf(), but its name more accurately describes the action of adding back the previous set of elements from the internal stack. Furthermore, .addBack() accepts an optional selector parameter, allowing developers to filter which previous elements are added to the current selection.

Updating to addBack()

To modernize legacy code, replace .andSelf() with .addBack():

// Legacy syntax (deprecated)
$("div.container").find("p").andSelf().css("border", "1px solid red");

// Modern syntax
$("div.container").find("p").addBack().css("border", "1px solid red");

// Optional filtering with addBack()
$("div").find("p").addBack(".special-div").css("color", "blue");