javascript--Selector

1, the selector is the foundation of jquery, in jquery, the event processing, traversal DOM and AJAX operations are dependent on the selector.

2, the advantages of choice:

--concise wording;

--perfect event handling mechanism.

3. Basic selector:

--The basic selector is the most commonly used selector in jquery and the simplest selector, which finds DOM elements through element Id,class and tag names (only once in a Web page, and class allows for reuse);

4. Hierarchy selector:

-If you want to get specific elements through hierarchical relationships between DOM, such as descendant elements, child elements, neighboring elements, sibling elements, etc., you need to use a hierarchy selector;

The--$ ("prev ~ div") selector can select only the sibling elements that follow the "#prev" element, whereas the method siblings () in jquery is independent of the position, as long as it is a sibling node;

5. Filter selector:

--The filter selector primarily filters out the required DOM elements through a specific filtering rule, which begins with ":";

Filter selectors can be divided into basic filtering, content filtering, visibility filtering, attribute filtering, sub-element filtering and Form object attribute filter selectors according to different filtering rules;

--1) Basic Filter Selector:

--2) Content Filter Selector: The filtering rules of content filter selectors are mainly embodied in the sub-elements and text content;

--3) Visibility Filter selector: Selects the appropriate element based on the visible and invisible state of the element;

--Visible Selector: The hidden contains not only elements of the style property display as none, but also elements such as the text-hiding field (<input type= "hidden"/>) and Visible:hidden;

--4) Property Filter selector: Gets the corresponding element by its attributes

--5) child element filter selector:

The--nth-child () selector is detailed below:

--①:nth-child (even/odd): The element that can select the index value under each parent element is even (odd) number;

--②:nth-child (2): You can select an element with an index value of 2 under each parent element;

--③:nth-child (3n): can select the element under each parent element that the index value is a multiple of 3;

--④:nth-child (3n+1): can select each parent element under the index value is 3n+1 element;

--6) Form object property Filter Selector: This selector primarily filters the selected form:

--7) Form selector:

javascript--Selector