For example
Copy Code code as follows:
settimeout (function () {alert (' Hello! ');}, 0;
SetInterval (callbackfunction, 100);
It is assumed that the greeting method in settimeout is executed immediately, because it is not a figment of the imagination, but rather a JavaScript API document that explicitly defines how many milliseconds the second parameter meaning is, and the callback method is executed. This is set to 0 millise
Traditionally, Javascript files are loaded using the script tag. We can also use the DOM method to dynamically load Javascript files. The specific implementation is as follows. If you are interested, refer to the traditional method, the script label is used to load Javascript files.
As shown below:
The javascript design pattern is turing Publishing. in learning, I want to focus on every chapter. Question:
1.1 javascript flexibility
Object-oriented Javascript programming mode: 1. Saving state 2. methods that can be called within an object 3. Better understanding of the structure of a program, able to withstand iterative development (in my opinion)
The Co
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Attribute
Method
1. Create an instance of the object
2. Create an object Template
Objects help organize information.Instance
Instance of the created object
This example shows how to create an instance of the javacripobject ).
Create an object Template
This example shows you how to create a template for a javacript object ).
JavaScript Object
In the previous section of this tutorial, we have learn
Javascript (1) Summary of javascript Array usage (2), javascript Array
// 1. array sorting. The default value is ascending. The sort () method calls the toString () of each item in the array, and then compares the obtained string to sort the result. // sort (): returns the sorted array // var arr = [23,1, 3,56, 42,-1]; // arr. sort (); // alert (arr); //-, // eve
Basic JavaScript instance
Generate text
Generate common text and tags
Head Section
Body section
External Javascript
ExampleJavascript statements, comments, and code blocks
Javascript statements
JavaScript code block
Personal Summary: It takes 15 minutes to finish this article, this article introduced the abstract syntax tree and JS engine parsing these syntax tree process, referred to lazy parsing-that is, the process of converting to AST is not directly into the function body parsing, when the function body needs to be executed when the corresponding conversion. (because some function bodies are simply declared, and are not actually called)Parsing, Syntax abstraction tree, and 5 tips for minimizing parsing
Javascript learning diary-prevents javascript events from bubbling and obtains the Control ID value
1. How to Prevent event bubbles
The Code is as follows:
// Non-IEIf (event event. stopPropagation)Event. stopPropagation ();Else // IEWindow. event. cancelBubble = true;
2. Get the Control ID
The Code is as follows:
If (document. all ){// IEAlert (event. srcElement. tagName + ":" + event. srcEl
How many seconds does function sleep in js? Javascript beginners often ask this question. Since the emergence of Javascript, this function is so necessary, but why does js not provide such a function?
Currently, all browsers parse js in the UI thread. Taking Firefox as an example, I re-compiled the js engine and added the sleep method to the js alert. This method calls the C language thread sleep functio
This article mainly introduces a simple example of implementing the TAB switch Effect of js (JavaScript). If you need it, you can refer to it and hope to help you with JavaScript) the tab Label Switching code of, can automatically adapt to the width, you can add and delete the label block yourself, you can complete the silly operation!
The Code is as follows:
19991224/loose. dtd ">
Adaptive width labe
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Instance 1
Instance 2
Syntax:
Instance
Syntax:
Instance:
The Condition Statement in Javascript is used to complete the action under different conditions.Instance
If statement
How to compile an if statement.
If... else statement
How to compile the IF... else statement.
If. Else if... else statement
How to compile the IF... else if... else statement
Random Link
This exam
This article mainly introduces how to increase the loading speed of javascript. write output js solves the problem of slow ad loading speed. If you need it, you can refer to it. Generally, some js Code will be loaded on our website, such as statistics, google ads, Baidu alliance, alimama advertising code,
The page loading speed was slow and slow.
Solution: Use a js inclusion method to increase the loading speed of
When JavaScript is used on pages, where should these JS code be placed? Next, let's learn how to use JavaScript on the page. where should these JS code be put? Let's take a look.
Generally, there are two ways to write on the interface and use. js files.
1.1 Head part on the interface
You can directly put it in the head label, as shown in the following code:
TestPage
We can use JavaScript to create dynamic images.Instance
Button Animation
Two different events are used to drive two corresponding functions, and two corresponding images are switched to create an animation effect.
Javascript Animation
It is feasible to create dynamic images using JavaScript.
TipsYes: use JavaSc
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Syntax
Instance
Instance-Infinite Loop
Syntax
Instance
By using JavaScript, we have the ability to execute code after a set interval, rather than immediately after the function is called. We call it a timing event.Instance
Simple timing
After you click the button in this example, a warning box will pop up in five seconds.
Another simple timing
In this example, the program runs 2 seconds, 4 seconds
Upgrade JavaScript (JavaScript you Don't know) to improve javascriptRecently, I have read the book "JavaScript (on-volume) You don't know", which details many important but often overlooked JavaScript points. I strongly recommend this book !!! In the book, Chapter 1 describes "Upgrade", describes the process of variabl
You can create three message boxes in javascript: Warning box, confirmation box, and prompt box.Instance
Warning box
Warning box with lines
Confirmation box
Prompt box
Warning box
The warning box is often used to ensure that users can obtain certain information.
When a warning box appears, you must click OK to continue the operation.Syntax:
Alert ("text ")Confirmation box
The confirmation box enab
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1:
2:
An array object uses a separate variable name to store a series of values.Instance
Create an array
Create an array, assign values to it, and then output these values.
For... in statement
Use the for... in Declaration to cyclically output the elements in the array.
Merge two Arrays-Concat ()
How to Use the Concat () method to merge two arrays.
Using array elements to form a string-join ()
How to Use the join ()
The string object is used to process existing character blocks.
Javascript string object instance
Calculate the length of a string
How to Use the Length attribute to calculate the length of a string.
Add a style to a string
How to add a style to a string.
Indexof () method
How to Use indexof () to locate the first occurrence of a specified character in a string.
Mat
What does JavaScript mean? What's the use? I believe there are a lot of students can have this question, then today's PHP Chinese network to give you a talk about the concept of JavaScript and what is the use of JavaScript.
What does JavaScript mean?
From the Baidu Encyclopedia we can find
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