difference between null and undefined in javascript

Before the cloud-dwelling community sent a similar articleJavaScript null and undefined difference analysisJavaScript undefined,null type and nan value differenceLet's talk about undefined:The variables in JavaScript are weakly typed (I don't need

1. Type analysis:JS data types have undefined,boolean,number,string,object, such as 5, the first 4 are the original type, the 5th is the reference type.CodeCode highlighting produced by Actipro Codehighlighter (freeware)

A bad time to answer, especially undefined, because this involves the realization of the principle of undefined. So, after thinking carefully, write down this article, please heroes to shoot bricks. Total known: null = = undefined However: null!==

When discussing the primitive data types in Javascript, most people know the basic knowledge, from String, Number to Boolean. These primitive types are quite simple and behavior is common sense. However, this article will focus more on the unique

Here is a collection of JS in the null and undefined two hints of the difference between analysis, for each beginner should have no small use OH. Generally known:Null = = undefinedBut:Null!== undefinedSo what's the difference between the

Similar articles have not been posted before.Difference between JavaScript null and undefined JavaScript Undefined, difference between the Null type and the NaN Value Let's talk about undefined:The variables in Javascript are of a weak type (I don't

Most computer languages have and have only one value that denotes "none", such as the nil of the None,ruby language of the Null,python language of the C language Null,java language. Oddly enough, the JavaScript language actually has two values that

Most computer languages have and have only one value that represents "none", for example, the Null,java language of the C language, the Null,python language of the None,ruby language of nil.Oddly enough, the JavaScript language actually has two

Most computer languages have and have only one value that represents "none", for example, the Null,java language of the C language, the Null,python language of the None,ruby language of nil.Oddly enough, the JavaScript language actually has two

In fact, I've listed all the "null" and "false" values in JavaScript, except that the Boolean value itself is true and false, "null values" for other data types are mainly undefined and defined. The types of these null values are: The