Detailed explanation of the basics of Dom exploration

Get to know DOM

DOM level

Note: The DOM level 0 standard does not actually exist, it is just a reference point for the historical coordinate system. Specifically, it refers to the DHTML originally supported by IE4.0 and Netscape Navigator4.0.

Node type

Note: 1. The node represents the attribute in the element. Because the attribute is actually attached to the element, the attribute node cannot be regarded as a child node of the element. In the DOM, the attribute node is not considered to be part of the document tree, that is, the attribute A node is considered part of the element node that contains it and does not appear as a separate node in the document tree. 2. The document fragment node serves as a placeholder when inserting the node. 3.IE does not support character constants (because IE does not have Node objects).

DOM ready

Html tags must be parsed by the browser before they become DOM nodes.


DOM ready is more optimized than window.onload.

Inheritance hierarchy and nesting rules

HTML nesting rules

Block and inline element nesting rules

• Block elements can contain inline elements or certain block elements, but inline elements can only contain inline elements.

• Special tags such as h1~h6, p, and dt can only contain inline elements.

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Reference material: MOOC - Detailed explanation of the basics of DOM exploration