null undefined

Today, I want to change the highlighted color of JS. This regular expression is generated in the afternoon.The old elders are a regular expression. Don't be scared when you see it. Copy codeThe Code is as follows:/(\/. * | \/\ * [\ S \ s] +? \ * \/)

This article mainly introduces the odd fake value application in JavaScript. For more information, see the following statement structure. If branch statement While loop statement The second statement in For example The Code is as follows: If

This article introduces the content of the second chapter of the seed module of the javascript Framework Design of situ zhengmei. It is a small post-reading experience. You can refer to it. The seed module is also called the core module, which is

This article mainly introduces the javascript method for determining whether a variable has a value. It can effectively determine the value, which is of great practical value, for more information about how to use javascript to determine whether a

for JavaScript "= =" and "= = =" Difference I think a lot of people should be very clear, examples:1==true//true1===true//falseWe usually judge two data, and the "= =" in JavaScript takes an implicit cast, while "= = =" means two data types are

I. Summary of source code ideas Summary:The core idea of jQuery can be simply summarized as "querying and operating dom". Today we mainly analyze the jQuery. prototype. init selector constructor to process parameters in the selector function;The

Basic concepts of JavaScript (iv) --- operators and javascript OperatorsOperator 1. unary operator The operator that can operate only one value is called The unary operator. The unary operator includes the increment (decrement) operator and the

ECMAScript is a dynamic language built on five simple data types (Undefined, Null, Boolean, Number, String) and one complex data type (Object. This article will review simple data types. I will try to describe them from the perspective of

There are two primitive types in javascript: null and undefined. These two types often make JavaScript developers confused, when is null, and when is undefined?The undefined type has only one value, which is undefined. When the declared variable has

ECMAScript5 added some details about the array APIThe array Methods Added by ECMAScript5 seem to be relatively simple. In fact, there are still some details that need to be understood. First, these methods do not apply to the original array, and

Introduction　　JavaScript is a very strange language to use in some situations. This article will try to gather together some of the more special usages of this language. It is a place to be aware of when developing at ordinary times.Special Usage

When some front-end controls need to submit data to the server for data verification, they need to determine whether the submitted data is empty. For string data of a common form, you only need to judge the length after trim, and the data needed

This article mainly introduces the types, values, and variable Summary of JavaScript. You can refer to the following: JavaScript data types are divided into two types: primitive type and object type. Five primitive types: Numbers, strings, Boolean

This article mainly introduces the basic knowledge of javascript, including string, special character operations, variable-to-String Conversion, and provides a comprehensive explanation of the basic knowledge of javascript. In order to better help

JavaScript is a weak type or dynamic language. This means that you do not need to declare the variable type in advance. During the program running, the type will be automatically determined. This also means that you can use the same variable to save

JavaScript is a weak type , or dynamic language. This means that you do not have to declare the type of the variable in advance, and the type is automatically determined during the program's run. This also means that you can use the same variable to

This article mainly introduces other related documents of the Jquery1.9.1 source code analysis series (15th) animation processing. For more information, see A. animation compatibility with Tween. propHooks Tween. propHooks provides methods to set

Implicit conversions in JS can usually be converted into corresponding data types through functions such as parseint (), number (), String (), and Boolean (), but usually for simplicity, we use a special notation, such as:var a = 5;console.log (A + "

Recently began to re-read the "JavaScript Advanced Programming", the memory of this is the third time, but the front is a cursory, this time still need to tidy up and practice.Although it is a basic concept, but there are a lot of easy to pay

A. JS has 5 basic types and 1 object types (reference types) 5 Basic types: Number\string\null\undefined\boolean 1 Types of objects: Function, Array, Date Two. Type conversion Skillfully type conversion with +/- Three. = = and = = = = =: 1. For