JavaScript

Front. The underlying syntax for JavaScript's regular expressions is described earlier. The RegExp class of JavaScript represents regular expressions, and both string and RegExp define methods, and regular expressions allow for powerful pattern

First, single selection 1. Which of the following statements will result in a run-time error: (a) A.var obj = ();//Syntax error B.var obj = [];//Create array C.var obj = {};//Create object D.var obj =//; Reason: var obj = new Array (); is right;

In the previous list of programming languages, we introduced the JavaScript language of the impending regularization, as illustrated in the article, that JavaScript is not only the most dynamic scripting language, but also one of the most useful

Series Introduction Perhaps, 300 years ago, Sir Isaac Newton (Sir Issac Newton, 1643-1727) had no illusions that physics was widely used in many games and animations today. Why do you use physics in these applications? The author believes that since

Knowledge Points: is primarily used for date objects. (The following information is from the network) to create the syntax for a Date object: var mydate=new Date () The Date object automatically saves the current date and time as its initial

Removing the spaces at each end of the string is a very common method of string processing, and unfortunately JavaScript does not have these three methods, only we have customized: Step 1th, add members to string Copy Code code as follows:

Previously discussed how to write in JavaScript. However, private implementations are not discussed. Look at this article. We know that the implementation of JS private property is the essence of Var + closure. As follows Copy Code code as

Definition of JavaScript function 1: Invoke the keyword function to construct, as:function distance (x1,x2,y1,y2){var dx=x2-x1;var dy=y2-y1;Return math.sqrt (Dx*dx+dy*dy);} 2: Use the function () constructorvar f=new function* "x", "Y", "return

In daily development, the conversion between color gamut values in different formats is often used, and a workaround is given below. Copy Code code as follows: Regular expressions for hexadecimal color values var reg =/^# ([0-9a-fa-f]{3

1. You cannot explicitly create a math object and use it directly; 2.Math objects cannot store data, unlike String,date objects; 3. Before you know the parseint () function will make a decimal integer (so 24.999 becomes 24) by eliminating

With the development of the network and the speed of the machine, more and more websites use the rich client technology. Now Ajax is one of the most popular ways. JavaScript is an interpreted language, so it can't reach the level of C/java and so on,

For decades, functional programming has been a favorite of computer science enthusiasts, because of the purity of mathematics and the nature of mysteries, which are buried in computer labs, only for data scientists and people who want to get a PhD.

JavaScript from definition to execution, JS engine in the implementation layer do a lot of initialization work, so before learning the JS engine working mechanism, we need to introduce a number of related concepts: Execution environment stack,

Closure (closure) is the concept of functional programming, appearing in the 1960s, the earliest implementation of the closure language is Scheme, which is a dialect of LISP. After that, closure features are widely absorbed in other languages.The

The scope and context (contexts) in JavaScript are unique to the language, thanks in part to the flexibility they bring. Each function has a different context and scope of variables. These concepts are backed by some powerful design patterns in

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

Calculates the number of weeks of the current date in this year Date.prototype.getWeekOfYear = function (Weekstart) {//Weekstart: Weekly start in week: Sunday: 0, Monday: 1, Tuesday: 2 ..., default to Sunday Weekstart = (weekstart 0)-0; if (isNaN

Javascript|request|xml|xmlhttprequest XMLHttp way to implement the brushless screen, tested on the Ie,firefox   "http://www.w3.org/tr/xhtml1/DTD/ XHTML1-TRANSITIONAL.DTD //Global flag var Isie = false; Global request and XML document

JavaScript variable names are subject to two simple rules: 1. The first character must be a letter, an underscore (_), or a dollar sign ($). 2, the remaining characters can be underlined, dollar sign or any letter or numeric character. Name Method: 1

Example of front-end paging Control Implemented by angularjs: angularjs Paging I wrote a jQuery paging display plug-in, which has many bugs. Now, due to business needs, I learned a little about AngularJS and implemented this paging plug-in with