DOM (Document Object Model) and BOM (Browser Object Model) are two commonly used manipulation object models in JavaScript programming. The DOM manipulates the HTML document, while the BOM handles manipulation of browser features such as the browser window and toolbars.
Detailed explanation of DOM:
DOM provides a way to represent HTML documents as a tree structure. Each node in an HTML document is a data type, such as element, attribute, text, and so on. Developers can use JavaScript to add, delete, modify, and query these nodes.
The root node of the DOM tree is the document object. The document object represents the entire HTML document, including all elements and attributes of the HTML document. Use the document object to get elements in the document, and to create new elements.
There are usually two ways to operate DOM, one is to use native DOM API, such as getElementById, createElement, etc.; the other is to use open source libraries, such as jQuery, React, etc.
Detailed explanation of BOM:
The BOM provides a way to access browser windows and toolbars and other browser functionality. BOM contains many objects, such as window, navigator, screen, history and location.
The window object represents the current browser window or tab. Developers can use the window object to access browser navigation history, timers, alert boxes, and more. You can also use the methods of the window object to open a new window, close the current window, adjust the window size, and so on.
The location object represents the location of the browser window containing the current document. Developers can use the location object to get the URL of the current document, modify the URL, open the URL in a new window, and so on.
The navigator object represents the browser itself, and developers can use the navigator object to obtain information such as the browser name, version, and operating system type.
The screen object represents the properties of the user's screen, such as screen resolution, color bits, etc.
The history object represents the history of the browser, and developers can use the history object to access the forward or backward history.
The difference between DOM and BOM:
DOM and BOM are both JavaScript's way of manipulating browser-related content, but they are quite different:
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The DOM primarily deals with the structure and content of the HTML document, while the BOM deals with the properties and behavior of the browser window.
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DOM can easily query and modify the elements and attributes of HTML documents, while most of BOM's access to browsers is read-only, and the attributes and methods in BOM are only allowed to be used by the browser itself.
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DOM is part of the specification defined in W3C standards, BOM is not.
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DOM is the document-related object model; BOM is the browser-related object model.
In short, both DOM and BOM are very important object models for developers, and developers need to understand their usage and differences. If you can use DOM and BOM flexibly, you can write efficient and elegant JavaScript code.