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jQuery - DOM Traversing


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jQuery is a very powerful tool which provides a variety of DOM traversal methods to help us select elements in an HTML or XML document randomly as well as in sequential method. Elements in the DOM are organized into a tree-like data structure that can be traversed to navigate, locate the content within an HTML or XML document.

Document Object Model (DOM) - is a W3C (World Wide Web Consortium) standard that allows us to create, change, or remove elements from the HTML or XML documents.

The DOM tree can be imagined as a collection of nodes related to each other through parent-child and sibling-sibling relationships and the root start from the top parent which is HTML element in an HTML document.

Before we start traversing a DOM, Let's understand the terminology of parent, child and sibling. Let’s see an example:

<body>
   <p>This is paragrah</p>

   <div><span>This is div</span></div>

   <button id="b1">Get width</button>
   <button id="b2">Set width</button>
</body>

In the above example, we have a <body> element at the top, which is called a parent for all the elements. The <div>, <p> and <button> elements inside the <body> element are called siblings. Again <span> element inside <div> is a child of <div> and <div> is called a parent of <span> element.

The <div> element is a next sibling of the <p> element and <p> is the previous sibling of the <div> element.

Traversing the DOM

Most of the DOM Traversal Methods do not modify the jQuery DOM object and they are used to filter out elements from a document based on given conditions. jQuery provides methods to traverse in the following three directions:

  • Traversing Upwards - This direction means traversing the ancestors (Parent, Grandparent, Great-grandparent etc.)

  • Traversing Downwards - This direction means traversing the descendants (Child, Grandchild, Great-grandchild etc.)

  • Sideways - This direction means traversing the ancestors the siblings (Brother, sisters available at the same level)

We will learn all the above traversing methods starting from the next chapter.

jQuery Traversing Reference

You can get a complete reference of all the jQuery Methods to traverse the DOM at the following page: jQuery Traversing Reference.

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