javascript learning for beginners

How to sort JavaScript learning notes _ setTimeout and javascript SetTimeou t Application var ids = [];function foo1(i) { this.i = i; console.log('i = '+i); ids[0] = setTimeout((function () { foo1(i); }),1000);}function foo2(j) { this.j = j; console.log('j = '+j); ids[1] = setTimeout((function () { foo2(j); }),1000);}foo1(2);foo2(3);clearTimeout(ids

PropertyWe get the Results:Change HTML StyleHTML DOM allows JavaScript to change the style of HTML elements. How do you change the style of HTML elements?Grammar:Object.style.property=new style;Note: object is the element that gets the element object, such as by document.getElementById ("id").Basic attribute Table (property):There are three ways to cancel a property setting(1) var obj = document.getElementById ("txt");Obj.removeattribute ("style");(2

basic js learning solution, which is very rough, but it is suitable for you to understand the overview of client js. Instances that can be tried immediately, or beginners of js can immediately see the results. Step 2: You need a book that systematically introduces javascript, such as the rhino book (javascript authori

A summary of javascript Learning (basic knowledge) and a summary of javascript every day 1. character conversion Var s1 = "01"; var s2 = "1.1"; var s3 = "z"; // the 'z' letter cannot be converted to a number, therefore, NaN var B = false; var f = 1.1; var o = {valueOf: function () {return-1 ;}; s1 =-s1; // value becomes numeric-1 s2 =-s2; // value becomes numeric

Javascript event binding learning points and javascript event binding Event binding can be divided into two types: traditional event binding (Inline model, script model) and modern event binding (DOM2 model ). Modern event binding provides greater and more convenient functions in traditional binding. A traditional event binding Problem Inline models in traditiona

Javascript asynchronous programming code writing specification Promise learning notes, promise learning notes Recently, my work was easy. I remembered the word promise which I used to see before. So I learned it with patience. I. What is Promise? Why is there this? First of all, Promise is designed to solve the problem of code writing in

Cookie object for JavaScript learning notes, learning notes cookie JavaScript Cookie Cookie object: Cookie is the user data (Cookie data) stored in the Cookies folder on the client's hard disk in the form of files ). The Cookie file is created by the accessed Web site to store session data between the client and the We

JavaScript Learning-Closures 1. What is closuresIn most books, closures are defined as "closures refer to functions that have access to variables in another function scope." ”。 The concept is too abstract to be helpful to beginners. Fortunately, the JavaScript Ninja Cheats 5.1 gives an example to further explain what a

Createcomparisonfunction function's execution environment, and then the Createcomparisonfunction function ends, The execution environment of the Createcomparisonfunction function is destroyed, but the active object of the Createcomparisonfunction function cannot be destroyed because it is referenced by the closure.When Comparenames executes, it still follows the execution flow of the normal function: Create the execution environment of the function; Create a scope chain for the exe

Generally, when javascript looks at the effect, alert functions are often used. Imagine if we want to see how many objects there are under the document, we may write the code like this: [javascript] for (iindocument ){... syntaxHighlighter. all (); generally, when javascript looks at the effect, alert functions are often used. Imagine if we want to see how many o

Objects (object):　　All things in JavaScript are objects, such as strings, numbers, arrays, functions, and so on, each with properties and methods. JavaScript provides multiple built-in objects, such as String, Date, Array, and so on.Properties of the object:　　Reflecting some specific properties of the object, such as: the length of the string, the long width of the image, etc.;Method of the object:　　An acti

All things in JavaScript are objects: strings, numbers, arrays, dates, and so on.In JavaScript, objects are data that owns properties and methods.A property is a value associated with an object.Method is an action that can be performed on an object.Tip: In an object-oriented language, properties and methods are often referred to as members of an object.The syntax for accessing object properties is:objectNam

only the internal loop, but also the External Loop. This occurs when j is equal to 5, which means that the internal loop will be reduced by 5 iterations, resulting in the iNum value being 95. Tip:It can be seen that the tag statements used in combination with break and continue are very powerful, but over-using them will cause trouble for debugging code. Make sure that the labels used are descriptive and do not nest too many layers of loops. The above is the summary of today's

and executes it as script code. GetClass () Returns the Javaclass of a javaobject. Isfinite () Checks if a value is a number that has a poor size. IsNaN () Checks whether a value is a number. Number () Converts the value of an object to a number. Parsefloat () Parses a string and returns a floating-point number. parseint () Parses a string and returns an integer. Strin

prototype method can only be called by objects of this class. A. prototype = new B (); The prototype looks like inheritance, but it is not actually, it is more like clone and more accurate If the parent class and subclass have duplicate attributes, use the proximity principle. If the first-level and top-level attributes cannot be found, use the call method to specify the attributes of the upper-level invocation. extendClass.prototype = new baseClass();var instance = new extendClass();var basei

matched string in the input. When regExp has a global sign (g option), it is very simple. In our understanding, it returns an array consisting of all matched strings. This is a standard array with no input or index attributes. The returned value array contains no information except the matched strings. From the analysis above, if you just want to determine whether the string matches a regular expression, use the test method. If you want to retrieve all matched strings at a time, or find only th

executes the source file, the code in the file is packaged into a function called Main. This main function is then used as the entrance to the program.In other words, suppose a JS file has such a code: var a = 1; var b = 2; function add (x, y) { var z = x + y; return z; } Console.log (Add (A, b)); The JS engine wraps the program into a main function before it starts executing: The fictitious main function function main () { var a = 1; var b = 2; function add (x

All things in JavaScript are objects: strings, values, arrays, and functions. Almost every js is inseparable from its js objects. In addition, JavaScript allows user-defined objects. The following is a summary of javascript Object learning in small series. For more information, see

JavaScript learning 10: Dynamic Loading of scripts and styles, javascript scriptsWhen writing web pages, we need to introduce a lot of JavaScript script files and CSS style files. Especially when there is a large demand for websites, the demand for scripts also increases. As a result, the performance of the website wil

The script in the HTML must be between the tags. The script can be placed in the 1. Older instances may use the type= "Text/javascript" in the 2. Writing habits: The usual practice is to put functions into the DOCTYPE HTML>HTML>Head>Script>functionmyFunction () {document.getElementById ("Demo"). InnerHTML="My First JavaScript Function";}Script>Head>Body>H1>My Web PageH1>PID= "Demo">A Paragraph.P>Buttontype