es5 javascript tutorial

1:ES5 IntroductionECMAScript 5.1 (or ES5 only) is a revision of the ECMAScript (JavaScript-based specification) standard. Similar to the HTML5 specification process, ES5 is standardized by merging existing JavaScript methods with the addition of statements and native ECMAScr

ES5 learning tutorial Array object, es5array object Preface Many new things added in ES5 will help us write Javascript. The following describes the Array objects in ES5. Let's take a look at them. 1. syntax for creating an Array object: new Array();new Array(size);new Array(

may be more convenient and faster. Why use ES5,ES6,TypeScript to demo ? Let's introduce these three concepts:ES5: Full Name ECMAScript5, which can be understood as our regular JavaScript(in fact JavaScript also contains the DOM and the BOM ), which is currently supported by most browsers JavaScript syntax characteris

quickly. But after ECMASCript 3 came out of 1999, there were no changes made to the official for a standard. Instead various browser vendors made their own custom extensions to the language, and Web developers were left to try and Support multiple APIs. Even after ECMAScript 5 is published in 2009, it took several years for wide browser support of the new spec, and most de Velopers continued to write code in ECMAScript 3 style, without necessarily being the aware. Around things started to cha

There are many methods for JavaScript inheritance, including compile-to-javascript TypeScript, CoffeeScript, and various polyfill implementations provided by the website MDN, GitHub, and Modernizr.From the perspective of ES5, some of these solutions are functional, but the semantics is not satisfactory.I have taken some trendy ideas from these schemes and compile

1, use strict mode, add code specification' Use strict 'This is a good habit to avoid some hidden errors in your code. Strict mode is used by default in ES62, JS ES5 Two ways to declare the method(function () { ' use strict '; // A function expression that assigns a method to a variable, which must be called after the declaration. // recommended ways to use the website var function () { }; // is a function declaration, it will be

1.JavaScript is a dynamic language, the appearance of ES6 make up for JS in large projects on the weakness (with "class").Here is a basic knowledge of ES5:2.Unlike traditional object-oriented languages such as C + + or Java, JavaScript actually pressesGener no class. Everything in the language is object-based and relies on a prototype (prototype) system. andThe p

There's a lot of new stuff in ES5, and knowing it helps us write JavaScript, like arrays, we probably don't need to rhythmic for loops. The write array method is added to the ES5, as follows: ForEach (JS v1.6)Map (JS v1.6)Filter (JS v1.6)Some (JS v1.6)Every (JS v1.6)IndexOf (JS v1.6)LastIndexOf (JS v1.6)Reduce (JS v1.8)Reduceright (JS v1.8) 1, JS commonly used

, isextensible.14.SymbolsSymbol is a basic type. The symbol is generated by calling the symbol function, which receives an optional name parameter, and the symbol returned by the function is unique.var key = Symbol ("key"); var key2 = Symbol ("key"= = Key2 //false15.PromisesPromises is an object that handles asynchronous operations and uses a Promise object to organize the code in a chained way, making the code more intuitive (like jquery's deferred object).functionfakeajax (URL) {return NewPro

.PromisesPromises is an object that handles asynchronous operations and uses a Promise object to organize the code in a chained way, making the code more intuitive (like jquery's deferred object).functionfakeajax (URL) {return NewPromise (function(Resolve, reject) {//settimeouts is for effect, typically we would handle XHR if(!URL) { returnSetTimeout (Reject, 1000); } returnSetTimeout (Resolve, 1000); });}//no URL, Promise rejectedFakeajax (). Then (function() {Console.log (' Success

traverses through to the end. The reduceright () begins with the last item in the array and traverses forward to the first item. Both methods receive two parameters: a function that is called on each item and (optionally) as the initial value for narrowing the base. the functions passed to reduce () and Reduceright () receive 4 parameters: the previous value, the current value, the index of the item, and the array object. Description: Use the reduce () method to perform an operation that evalua

the symbol function, which receives an optional name parameter, and the symbol returned by the function is unique.var key = Symbol ("key"); var key2 = Symbol ("key"= = Key2 //false15.PromisesPromises is an object that handles asynchronous operations and uses a Promise object to organize the code in a chained way, making the code more intuitive (like jquery's deferred object).functionfakeajax (URL) {return NewPromise (function(Resolve, reject) {//settimeouts is for effect, typically we would ha

The ES5 syntax does not support class classes, but you can declare a class by clearing the function as follows:function person (name) {This.name=name;}var john=new person (' John ');Console.log (john.name);//johnBut this class can be called directly like function execution: person ()The decision is not to be called by New or () so modify the above class:function person (name) {This.name=name;if (this instanceof person) {Alert (' New call ');}else{Aler

Reference Type of the JavaScript getting started tutorial and javascript getting started tutorial Reference Type A reference type is a data structure used to organize data and functions together. It is also often called a class, but this name is not appropriate. Although ECMAScript is technically an object-oriented lan

JavaScript Tutorial Series 49:javascript Tutorial: The prototype chain is immutable

This tutorial provides a relatively complete basic knowledge for those who have not been familiar with JavaScript, but only limited to the basic knowledge. JavaScript reference This tutorial provides a relatively complete basic knowledge for those who have not been familiar with J