what use strict

Vars in perl is a pragma (precompiled indicator) in perl that is used to predefine global variables. These predefined global variables are in the qw () list, it can be used in the entire referenced perl file. Even if you use strict, no error is

This article describes how to use Promise in JavaScript. The promise object is an important knowledge point in JS advanced learning. If you need it, you can refer to many languages, to process the asynchronous mode in a more general order, it

This article describes how to use Promise in JavaScript. The promise object is an important knowledge point in JS advanced learning. if you need it, you can refer to many languages, to process the asynchronous mode in a more general order, it

In the ES6 new fast-scope concept (C language, as C-language JS, of course, should be added), is very good understanding.{let i;} Console.log (i); // i am not definedUse the new scope in the code block.The problem is that the FOR statementLet arr=

Life is not right and wrong, only after the choice of persistence, do not regret, go down, is right. React Native Project Directory Resolution In the previous section we simply built a new react native project Awsoneproject, and

PHP and SQL injection attacks. SQL injection attacks are the most common means for hackers to attack websites. If your site does not use strict user input tests, it is often vulnerable to SQL injection attacks. SQL injection attacks are usually the

PHP and SQL injection attacks [1]. Haohappyblog. csdn. netHaohappy2004SQL injection attacks are the most common means for hackers to attack websites. If your site does not use strict user input check, it is very vulnerable to

The author of this article is mainly designed to explore the source code of jquery, many people say that jquery design is too individualistic, in fact, this is a certain bias, because good design is universal, common, jquery so easy to use, how can

ZhuanHttp://www.ruanyifeng.com/blog/2013/01/javascript_strict_mode.htmlIn addition to the normal operating mode, ECMAscript 5 adds a second mode of operation: "Strict mode" (strict). As the name implies, this mode allows JavaScript to run under

Use Strict is a feature of ECMASCRIPT5 and is not recommended to be used globally, because when you compress different files, a file uses the use strict, a file that is not used, and does not use strict will be error-free.1. RoleEliminate the

1th: Understand the JS version you useMany JS engines support the const keyword definition variable, but the ECMAScript standard does not define any semantics and behavior about the const keyword. Also, the behavior of the Const keyword is different

JS built in a lot of classes, we use, are from these classes are instantiated.1 function Object () {} 2 function Array () {} 3 function String () {} 4 function Boolean () {} 5 function Function () {}For example, var a = {}; equals var a = new Object

Global executionFirst, let's look at what it is in the global context:Browser:Console.log (this);Window {speechsynthesis:speechsynthesis, caches:cachestorage, Localstorage:storage, Sessionstorage:storage, Webkitstorageinfo:deprecatedstorageinfo

Mentioned earlier Angularjs's Factory,service,provider, this can be understood as PHP model, this model is not with HTML, today's directive, can also be interpreted as PHP model, Can also be understood as plug-ins, except that the model is HTML, for

I. Overview The so-called Singleton pattern, as the name implies, is only one instance of a class.So, when we create an instance, we have to determine if it already exists, and if it already exists, return to the existing instance,

Delete the key and javascriptobject in the middle of a Javascript Object This is not the case either. Go back to farming and you will Copy codeThe Code is as follows:Delete thisIsObject [key]OrDelete thisIsObject. key By the way, let's talk about

About the development of jquery plug-in has done a little research, I have also written a number of plugins, in their own team has also shared a lesson on the plugin. The beginning of the whole sleep of the very complex code, now look at the time is

The JavaScript No Overloading function is not overloaded. In the ECMAScript language, the function name is just a pointer (which can be considered as a reference). The following code:   "Use strict"; function sum (a, B) {return a + B;} console.

Recently re-review JS, the delete operator has been in the state of smattering, accidentally found an article, this made a very detailed explanation, read the feeling of enlightened, dare not exclusive, roughly translated as follows.Original address:

Hee Hee Recently playing Nodejs, in my study and understanding of the NODEJS implementation environment is mainly divided into three parts, first there will be a global object, and then in this global object contains a core module and file module