


JavaScript simple and efficient judgment of data type series functions By shawl.qiu_javascript skills
Note:
When I almost mastered ASP VBScript some time ago, I switched to learning Javascript/Jscript, mainly Jscript.
However, there is basically no difference between the two. The only difference is that Jscript does not have a client. Concept.
At the beginning, I found that many practical functions of VBS were not available in JS, such as formatNumber, isArray, isDate, etc.
The date object is also very strange, and cannot be directly added, subtracted or subtracted. , you need to set***...
But when you master Javascript/Jscript to a certain extent, you will find that it is N times better than VBS. The advantage lies in its free grammar, which VBS does not have. For a certain function, you only need to create a prototype or a judgment function in JS to achieve the same function. Another obvious advantage is that regular rules can be used everywhere. .
Directory:
1 Determine whether it is an array type
2 Determine whether it is a string type
3 Determine whether it is a numeric type
4 Determine whether it is a date type
5 Determine whether it is a function
6 Determine whether it is an object
shawl.qiu
2006-11-13
http://blog.csdn.net/btbtd
1 Determine whether it is an array type
linenum
2 Determine whether it is a string type
linenum
3 Determine whether it is a numeric type
linenum
4 Determine whether it is a date type
linenum
5 Determine whether it is a function
linenum
<script> <BR>//<![CDATA[ <BR> var a=[0]; <BR> document.write(isArray(a),'<br/>'); <BR> function isArray(obj){ <BR> return (typeof obj=='object')&&obj.constructor==Array; <BR> } <BR>//]]> <BR></script><script> <BR>//<![CDATA[ <BR> document.write(isString('test'),'<br/>'); <BR> document.write(isString(10),'<br/>'); <BR> function isString(str){ <BR> return (typeof str=='string')&&str.constructor==String; <BR> } <BR>//]]> <BR></script>6 Determine whether it is an object <script> <BR>//<![CDATA[ <BR> document.write(isNumber('test'),'<br/>'); <BR> document.write(isNumber(10),'<br/>'); <BR> function isNumber(obj){ <BR> return (typeof obj=='number')&&obj.constructor==Number; <BR> } <BR>//]]> <BR></script><script> <BR>//<![CDATA[ <BR> document.write(isDate(new Date()),'<br/>'); <BR> document.write(isDate(10),'<br/>'); <BR> function isDate(obj){ <BR> return (typeof obj=='object')&&obj.constructor==Date; <BR> } <BR>//]]> <BR></script>

The main difference between Python and JavaScript is the type system and application scenarios. 1. Python uses dynamic types, suitable for scientific computing and data analysis. 2. JavaScript adopts weak types and is widely used in front-end and full-stack development. The two have their own advantages in asynchronous programming and performance optimization, and should be decided according to project requirements when choosing.

Whether to choose Python or JavaScript depends on the project type: 1) Choose Python for data science and automation tasks; 2) Choose JavaScript for front-end and full-stack development. Python is favored for its powerful library in data processing and automation, while JavaScript is indispensable for its advantages in web interaction and full-stack development.

Python and JavaScript each have their own advantages, and the choice depends on project needs and personal preferences. 1. Python is easy to learn, with concise syntax, suitable for data science and back-end development, but has a slow execution speed. 2. JavaScript is everywhere in front-end development and has strong asynchronous programming capabilities. Node.js makes it suitable for full-stack development, but the syntax may be complex and error-prone.

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JavaScript can be used for front-end and back-end development. The front-end enhances the user experience through DOM operations, and the back-end handles server tasks through Node.js. 1. Front-end example: Change the content of the web page text. 2. Backend example: Create a Node.js server.

Choosing Python or JavaScript should be based on career development, learning curve and ecosystem: 1) Career development: Python is suitable for data science and back-end development, while JavaScript is suitable for front-end and full-stack development. 2) Learning curve: Python syntax is concise and suitable for beginners; JavaScript syntax is flexible. 3) Ecosystem: Python has rich scientific computing libraries, and JavaScript has a powerful front-end framework.

The power of the JavaScript framework lies in simplifying development, improving user experience and application performance. When choosing a framework, consider: 1. Project size and complexity, 2. Team experience, 3. Ecosystem and community support.

Introduction I know you may find it strange, what exactly does JavaScript, C and browser have to do? They seem to be unrelated, but in fact, they play a very important role in modern web development. Today we will discuss the close connection between these three. Through this article, you will learn how JavaScript runs in the browser, the role of C in the browser engine, and how they work together to drive rendering and interaction of web pages. We all know the relationship between JavaScript and browser. JavaScript is the core language of front-end development. It runs directly in the browser, making web pages vivid and interesting. Have you ever wondered why JavaScr


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