SEARCH KEYWORD -- Scope


  Name resolution order in JavaScript

To understand what value a variable has in JavaScript, we need to understand some concepts such as scope and name resolution order. JavaScript has two scopes; one is program level and the other one is function level. Unlike in C,C++ or Java, JavaScript has no block level scope. So a variable defined in a if block will still be available outside. For example, the below example: var foo = 1; function bar() { if (true) { var foo = 10; } alert(foo); } bar(); The alert will display 10 since the ...

   JavaScript,Scope,Name resolution     2013-07-10 01:29:28

  Strict mode in JavaScript

1. Introduction In addition to normal mode, ECMAScript 5 includes the other mode : strict mode. It means it will make JavaScript codes execute in a more strict environment. The purposes to have strict mode are: Remove some unreasonable and parts of JavaScript syntax. Reduce some of the quirk behaviors. Remove some insecure parts of code execution. Make the execution environment more secure Improve interpret efficiency and increase the execution speed Build foundation for future JavaScript versi...

   JavaScript, Strict mode. Introduction     2013-01-17 05:00:26

  var in JavaScript

Geoff published an article sometime ago--"How one missing var ruined our launch". This article described one case where MelonCard uses Node.js as their backend system, suddenly there was a small registration peak period--50-100 people registered concurrently, then the entire website stopped responding and many other strange problems showed up. When they were investigating the source of the problem, they found one missing var in the following code.app.all(‘/apps/:user_id/status’, fun...

   JavaScript,Scope,variable     2012-05-26 12:35:36

  Understanding JavaScript closure and where it can be used

Closure The official definition of closure is: an expression (usually a function) that has many variables and is bound to an environment that includes those variables. In JavaScript, closure refers to the ability of a function to access the lexical scope in which it was defined, even after the function has been executed and left that scope. This ability is due to the fact that when a function is created, it generates a closure that includes a reference to the definition environment of the curr...

   CLOSURE,JAVASCRIPT,USAGE     2023-03-05 02:17:08

  this in JavaScript in detail

this in JavaScript is always confusing, it is one of the most frequently seen traps in JavaScript. this is not a good design in JavaScript(You can refer some other design flaws of JavaScript here), since it's lazy binding feature, it can be a global object, the current object or.... Some people even avoid using this in JavaScript. Actually if you master how this works, then you will know how to stay away from these traps. Let's take a look at what this points to in below situations. 1. In global...

   JavaScript,this,bind     2013-05-09 18:35:12

  4 ways to obtain access token in OAuth 2.0

OAuth 2.0 is an authorization mechanism, it's ,mainly used for issuing access token. There are 4 ways to obtain access token as per RFC 6749. Authorization code Implicit Password Client credentials The third party application must obtain a client id and client secret from the target service before obtaining access token no matter which method to use. This is to prevent token to be used maliciously. Authorization code With this method, the third party application must first get an authorization...

   OAUTH2,ACCESS TOKEN,REFRESH TOKEN     2019-06-29 07:12:03

  Alibaba CEO Daniel Zhang is no longer president of Taobao Software Co. Ltd

According to a recent change record from Chinese company registration information portal, the Chinese e-commerce giant Alibaba Group CEO Daniel Zhang is no longer the president of TaoBao Software Co. Ltd. His successor is Shan Dai, who is one of the founders of Alibaba and now Taobao CEO. Along with the change, Daniel also quits as the president of Tmall technology company which is also one of the subsidiaries of Alibaba Group focusing on big brands. Taobao (China) Software Co., Ltd. was establ...

   CEO,ALIBABA,TAOBAO,DANIEL ZHANG     2022-04-24 07:45:48

  Disgusting programming language list

To avoid arguments among different programming languages, this ranking only covers the opinions from programmers with multi-language experience. Also it doesn't mean the language is not good if the language is on the list, it just means those developers don't like some features of the language. Below ranking is summarized from Quora、Stack Overflow and Hacker News. 10. Python Reason : It uses code indent to define block level scope, why not use curly braces? It also uses massive colons and ...

   Programming language rank     2013-09-27 09:53:39

  Break down defer statements in GoLang

Basic Concepts What are the characteristics of the deferred statement defer in Go language? When is it usually used? The deferred statement(defer statement) in Go language has the following characteristics: Deferred Execution: Deferred statements are executed before the function containing them exits, regardless of whether the function returns normally or encounters an exception. Last In, First Out (LIFO): If there are multiple deferred statements, they are executed in the order of last in, f...

   DEFER,GOLANG     2024-02-10 21:56:10

  Alibaba founder Jack Ma sets up a new company

On November 24th, according to TianYanCha(A Chinese website to check company registration information), Hangzhou Majia Kitchen Food Co., Ltd. was established on November 22nd. The legal representative is PAU JASON JOHN, and the registered capital is 10 million RMB. The ownership information shows that the company is wholly owned by Hangzhou Dajingtou Er Shi Er Hao Cultural Art Co., Ltd., of which Alibaba founder Jack Ma holds a 99.9% stake. The business scope of this new company includes food ...

   JACK MA,ALIBABA,FOOD     2023-11-24 04:19:11

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