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Javasscript has 5 simple data types (also a basic data type): Undefined, Null, Boolean, number, String 1 of complex data types: Object The data type of all values in JavaScript is one of the above 6 types. So we need a way to detect what type of

1) Intro Not long ago I set up a technology group in a MM asked a question like this, she posted the code as follows: var a = 1;function hehe (){Window.alert (a);var a = 2;Window.alert (a);}Hehe (); The results of the execution are as follows:

3 problems related to the scope chain The scope chain is a very red concept in the JavaScript language, and many programmers who learn and use the JavaScript language know that the scope chain is key to understanding some of the most important

4 issues related to this, new, call and apply The principle of this pointer is a very complicated question, and if we illustrate this from the implementation mechanism of this in JavaScript, many friends may become more and more confused, so this

Modular programming is a very common form of JavaScript programming. It generally makes the code easier to understand, but there are many good practices that are not widely known. In this article, I will review the basics of JS modular programming

Closures have been heard in the first contact with JavaScript. The first thing to be clear is that it does not understand complexity, and it is very useful. So what are the basics before we get to know about closures? I personally think that the

In JavaScript, the callback function is specifically defined as: function A is passed to another function B as an argument (a function reference), and this function B executes function A. Let's just say function A is called a callback function. If

The above article has outlined the specific aspects of the console object as well as the basic application, here is a brief description of how to use the Chrome console this artifact to properly debug the JavaScript code (this is what we can really

Organize the JS object-oriented encapsulation and inheritance. 1. Package JS is packaged in a number of ways to implement, here are listed in several commonly used. 1.1 Raw Pattern Generation objects Write our members directly into the object

Doing the project is a learning process! As a learning C3, from C programmers to the front end, many of the rules in JavaScript is no way or say 1:30 will not understand. I met one today, which is roughly the code. var A; Global variablesfunction

My last blog title is wrong, causing some misunderstanding. I think the purpose of blogging is not to recite textbooks, but to share research and development experience. My last title was changed to "one of the topics of JavaScript closures: its

Let's look at the closure's purpose. In fact, we can do a lot of things by using closures. For example, simulate object-oriented code style, more elegant, more concise expression of code, in some ways to improve the efficiency of code execution. 1

Deep understanding of JS closures Closures (closure) are a difficult and unique feature of the JavaScript language, and many advanced applications rely on closure implementations. Scope of a variable To understand closures, you must first understand

Closure is a relatively abstract concept, especially for the JS Novice. The explanation in the book is rather obscure, and it is the same for me. But he is also JS ability to improve the one link can not be bypassed, almost every interview must ask

Overview You can use a timer to speed up the process of running your code. You can give each timer a name, and you can run up to 10,000 timers on each page. When you invoke the Console.timeend () function by using the timer name, the browser returns

As Web sites become "Internet apps," JavaScript code embedded in Web pages is growing larger and more complex. Web pages are more and more like desktop programs, need a team division of work, progress management, unit testing and so on ...

JavaScript's "Concurrency Model" is based on the event loop. This concurrency model differs from Java multithreading, and JavaScript concurrency is single-threaded. I simply drew a JavaScript execution diagram, and we went through the diagram to

Before we talk about the shallow copy and deep copy of JavaScript, we need to discuss the data type of JS. We all know there are five types of number,boolean,string,null,undefined,object. And object also contains Function,array and object itself.

Generally in programming, we will define functions and variables to successfully construct our system. But how does the parser find the data (functions, variables)? What happens when we refer to the object we need? Many ECMAScript programmers know

Dynamic request data to update the page is now a very common method, such as blog comments page dynamic loading, micro-blog scrolling load and timed request loading. In these cases, the data returned by the dynamic request is generally not a