The most basic filtering methods are first(), last() and eq(), which allow you to select a specific element based on its position in a group of elements.
Other filtering methods, like filter() and not() allow you to select elements that match, or do not match, a certain criteria.
With jQuery you can traverse sideways in the DOM tree to find siblings of an element.
Siblings share the same parent.
There are many useful jQuery methods for traversing sideways in the DOM tree:
siblings()next()nextAll()nextUntil()prev()prevAll()prevUntil()With jQuery you can traverse down the DOM tree to find descendants of an element.
A descendant is a child, grandchild, great-grandchild, and so on.
Two useful jQuery methods for traversing down the DOM tree are:
children()find()jQuery traversing, which means “move through”, are used to “find” (or select) HTML elements based on their relation to other elements. Start with one selection and move through that selection until you reach the elements you desire.
The image below illustrates an HTML page as a tree (DOM tree). With jQuery traversing, you can easily move up (ancestors), down (descendants) and sideways (siblings) in the tree, starting from the selected (current) element. This movement is called traversing – or moving through – the DOM tree.
Illustration explained:
An ancestor is a parent, grandparent, great-grandparent, and so on.
A descendant is a child, grandchild, great-grandchild, and so on.
Siblings share the same parent.
jQuery provides a variety of methods that allow us to traverse the DOM.
The largest category of traversal methods are tree-traversal.
The next chapters will show us how to travel up, down and sideways in the DOM tree.