Practical JS Series--bom common Objects

Background:

Recently, when embarking on the project, I realized the lack of JS. Although I've seen a lot of javascript videos, it's not always a big, hard case in a real project. So the basics of JavaScript need to be solid, and there's a series of blogs. This series of more emphasis on practical, theoretical parts can be see before the blog.

The BOM (Browser object mode) browser objects model is an important part of JavaScript. It provides a series of objects that are used to interact with browser windows, which are commonly referred to as BOMs.

As can be seen from the diagram, the Window object is the parent object of all objects in the BOM.

1. Window Object--bom Core

Window object, as the name implies.

It represents the entire browser window and is used primarily to manipulate the browser window.

The operation of the window is mainly the adjustment of coordinates, the screen coordinates as shown:

The common methods are:

1) Relative operation

moveby--Mobile

resizeby--resizing

2) Absolute operation

MoveTo

Resizeto

2. Document Object

It is a property of the Window object that can be used to work with the page document, but many features are deprecated.

Examples of common methods:

<script type= "Text/javascript" >        function Test () {            //Navigate to New page            document. URL = "http://www.baidu.com"            //output content            document.write (document. URL);  Window.document.write (document. URL) function same        }    </script>

3. Location Object

It is a property of the Window object and the Document object that is used to parse and set the URL address of the page.

Examples of common methods:

           URL attribute similar to document            location.href= "http://baidu.com";            Reload page            location.reload (TRUE);

4. Navigator Object

is considered to be the most important object, it contains a series of browser information properties.

UserAgent is the most commonly used property to complete the browser's judgment.

            var auseragent = navigator.useragent;             document.write (auseragent);

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5. Screen Object

is also one of the properties of the Window object and is used primarily to obtain the user's screen information.

Examples of common methods:

document.write ("screen height is:" + screen.availheight+ "" + "screen width is:" +screen.availwidth);

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Summarize:

JavaScript is the foundation. JavaScript is not good, but directly to use the functions provided in jquery, there is a sense of knowledge overhead. Know it, do not know why. JS can also help you understand the Ajax, so, JS learned to use, to be able to use, rather than write a simple registration event to Baidu, so inefficient, too unprofessional.

Practical JS Series--bom common Objects