javascript learning for beginners

Introduction to JavaScript1.javaScript is the most popular scripting language on the Internet, which can be used for Web and HTML, and can be widely used in server-side, PC-side, mobile-side.2.javaScript scripting language:JavaScript is the first lightweight programming language.JavaScript is a programmatic code that can be inserted into an HTML page.JavaScript can be interpreted and executed by all browser

= [123 ']for (var i in a) { alert (i) //0 1 2 Print key value alert (A[i])//Print value, array-like Operation}/ /Method Two: Specification for loop [recommended format]var b= [, ' 123 ']for (var i=0;iWhile Loop : For loops that already know the number of cycles-------------------while Loop------------------var i=1;var ret=0;while (iException handlingtry { //This piece of code runs from top to bottom, where any one of the statements throws an exception the code block ends running}ca

have already been involved in explaining why you are learning JavaScript. Here we will learn more complex things to manipulate HTML elements andCSS style, this will make the Web page dynamic, drop-down menus and pictures seamless scrolling and other dynamics, we can achieve. These are the things we need to learn later.Things up. Will not say more, this piece of knowledge to summarize.If you want to see the

Javascript system, Array object learning notes, array learning notes An array is a set of values in order. The attribute names of objects are unordered. In essence, arrays use numbers as search keys, and objects have custom attribute names. Javascript does not actually associate arrays, but objects can be used to imple

Function object of JavaScript learning notes, learning notes function In JavaScript, function functions are objects. JS does not support method overloading. In JavaScript, there is no concept of method (function) overloading. Example: Copy codeThe Code is as follows: The dia

Easy Learning of JavaScript 12: JavaScript Object creation based on object-oriented (1) This time, we will take a deeper look at the JavaScript object-oriented technology. Before learning, we need to explain some object-oriented terms. This is what all faces object languages

Zhang Xiaoxiang's JavaScript learning stage summary (2) -- (X) the HTML part of Zhang Xiaoxiang's JavaScript-HTML has been read over the past two days, and the focus of HTML is summarized. When reading the two chapters of HTML, you don't have to go into it. Some are dynamic, and some are outdated (obsolete usage and syntax. (1) The HTML version introduced in t

delete anode, but does not know which parent node it is, you can use the ParentNode property to help resolve it.Alert ("I pop up before being deleted!") ");//Get Id=" BJ "of the corresponding element sub-node var bjnode=document.getelementbyid (" BJ ");//Use ParentNode property to Id=" BJ " Remove BjNode.parentNode.removeChild (Bjnode) from the child node;Before deleting:after deletion:We continue to expand by adding a cofirm () System dialog box to each LI element node in the document to confi

[Front-end learning notes] native Javascript uses JSONP (common front-end methods) for cross-origin, learning notes jsonp Ajax cross-origin -------------------------- Cross-origin: When a file under a cross-origin domain name is requested for a resource file under a different domain name from another file, a cross-origin request is generated. This is the cross-o

The data types of JavaScript fall into two categories: primitive type (primitive type) and object type.There are 5 types of primitive type (also simple data type/basic data type): Number, String, Boolean, Null, Undefined.JavaScript does not support any mechanism for creating custom types, and all values will eventually be the original type or object type.At first glance, it seems that only these 6 data types are not enough to represent all of the data

Sort out the Javascript function learning notes. A series of previous articles are about the study of Javascript. This article is about the further study of Javascript Functions. I hope you will continue to pay attention to it. 1. What is a function? If you need to use the same piece of code multiple times, you can enc

other statements(1) Break statement: Used to jump out of a loop. for (Var box=1;boxThe result of the operation is:Execution to the fourth cycle no longer executes, jumping out of the cycle, the output of less box=5 after the cycle.(2) Continue statement: Used to skip an iteration in the loop. for (Var box=1;boxThe result of the operation is:Execute to the fourth cycle, jump out of the fifth cycle, continue to the following, output less box=5.(3) With statement: Set the scope of the code

There are two ways to add JavaScript code to the HTML code, that is, to use the 　　Async Script Async:This property is a new property of HTML5, similar to the Defer property, which is a property that alters the behavior of external script execution. Tags As a result, there are three ways to execute an external script:　　　　if async= "Async": The script executes asynchronously relative to the rest of the page (when the page resumes parsing, the scr

; alert(result); //false alert(typeof falseObject); //object alert(typeof falseValue); //boolean alert(falseObject instanceof Boolean); //true alert(falseValue instanceof Boolean); //false Boolean Object DescriptionIn JavaScript, a Boolean value is a basic data type. A Boolean object is a Boolean object that packs a Boolean value. A Boolean object is mainly used to convert a Boolean value to a string's toString () method.When the toString () m

object.When the bind () method is called on the function f () to pass in the object O, this method returns a new function that is invoked as an O method when the new function is called.Third, function constructorfunction () constructorThe function () constructor can pass in any number of string arguments, and the text represented by the last argument is the body. The function () constructor runs JavaScript to create and compile functions dyn

);//output: 1The result of the operation becomes 1, which proves that this represents the Obj object.After reading these basic is also JS basic tutorial inside the detailed, for some advanced JS tutorial also have more detailed explanation and examples. If you want to knowThe more detailed this mechanism, you can see the following three articles, since it is still not quite understood, in the back of the study need to strengthen the understanding of this. These three articlesArticle from Csdnyve

behaves differently in promiscuous mode, so it is recommended to declare the document type at the beginning of the HTML document.For standard mode, the browser makes the document performance and behavior as standard as possible, with three ways of declaring it:Then there are quasi-standard patterns, using transitional (transitional) or frameset (FRAMESET) document type trigger, their writing is not listed, see DOCTYPE at a glance. Quasi-standard mode and standard mode of performance are basical

=LastName; This. Age=Age ; This. Eyecolor=Eyecolor; //add a method to a JavaScript object This. ChangeName=ChangeName; functionChangeName (name) { This. LastName=name; }} myfather= NewPersionv ("Bill","GateV1", the,"Red"); document.write (Myfather.firstname+ " is" +Myfather.age+ "years old."); Myfather.changename ("hehehe"); document.write (Myfather.firstname+ " " +Myfather.lastname+ " is" +Myfather.age+ "years old.");Script>Body>HTML> ac

CSS styles as an aid to HTML can enhance the appearance of the page. I learned DOM to manipulate HTML, so we have to learn dom to manipulate CSS.The method of the style. When learning CSS, we already know that there are three cases of CSS inserting into HTML documents: inline, inline, and out-of-the-line(This is our most used). Here's how to operate these three scenarios:One-action inlineTo write an HTML document first:Any HTML element tag will have a

In JavaScript, I am neither an expert nor a master. However, JavaScript may be of some reference value in understanding JavaScript books from confusion. Recommended books for beginners: Javascript DOM programming Art I did not read it four times at the beginning. The b