null undefined

Operators include: arithmetic operators, bitwise operators, relational operators, and equality operators.Unary operator1, can only operate a worthy operator, that is, increment and decrement operators;2, Increment (+ +) and decrement (-) operators

1. Type conversion01) Other data types to Boolean type conversionsConvert by Boolean () function"Boolean true false"String non-empty Strings ""Number any non 0 0 and NanObject NULL for any objectsUndefined N/a Undefined (n/a not applicable not

About the = Operator and if Statement of js As we all know, these two are related to boolean values. The operator = returns a Boolean value, and the if () or ternary operator? : Boolean values are determined. In js, The = Operator and = operator are

The call, apply, and bind methods in Javascript are described and summarized in detail, applybind The following content is divided into the following sections: 1. Source of the call/apply/bind method 2. Function. prototype. call () 3. Function.

JavaScript basic Data typeThere are 6 kinds of data types in javascript: Null, Undefined, Boolean, String, number, Object. Where object is a complex data type.Basic data type: Null, Undefined, Boolean, String, number.Reference data type: Object,

Distinguish JS in the Undefined,null, "", 0 and FalseIn the various data types defined in the programming language, we will define a null value or a false value for it, such as a null value for the object type null,.net the null value of the

Rules for data type conversions 1 if there is only one value, judging whether this value is true or FALSE, follow only 0,nan, ' null,undefined these five are false and the rest are true 2 If two value comparisons are equal, follow these rules:

1. Convert other data types to number typeNumber (), strictParsefloat/parseint-Not strict1) Convert the Boolean type to a number true->1 false->02) Convert null/undefined to digital null->0 Undefined->nan 10+null=10 10+undefined=nan3) Convert [] to

As a front-end worker, you should be aware of some JavaScript development history, JavaScript implementations, and versions. The basic concepts include syntax, keywords, variables, data types, operators, statement controls, and functions, and they

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)

1. Namespaces : JS inside the namespace is the use of object properties to expand. For example, a user defines a object with a B attribute and a C attribute under object A, while the B and C properties are objects. So a={b:{},c:{}}, then the user

Comparative judgment Comparison judgment is to compare two values and return a Boolean value that indicates whether the comparison condition is met. JavaScript provides a total of 8 comparison operators, and here's the difference between the strict

javascript| objects ================================================================================Qomolangma Openproject v0.9 Category: Rich Web ClientKey words: JS oop,js framwork, Rich Web client,ria,web

1. Original type (6 kinds): Number,string,boolean,null,undefined,object (Function,array,date) 2. Implicit conversion: "37"-7//30 "37" +7//377 Note the use of-+-rule conversion type: (1) num-0: Converts num type to number; (2) num+ "": Converts the

Attribute operations mainly introduce the implementation of the three interfaces prop, attr, and val. Compared with other interfaces, these three source code implementations are complex and more confusing, if you accidentally use the wrong interface

Record the test and interview experience of the front-end school recruitment for one push, and the front-end testPen exam photos written test answers computer basic questions (mandatory) 1. Slightly 2. memory overflow and Memory leakage Memory

Javascript is a dynamic scripting language for (based) objects. It is a scripting language based on Object and EventDriven and has security performance. He has various characteristics specific to object-oriented languages, such as encapsulation,

This article introduces the JavaScript language to professional programmers. It is a small language. This article introduces the JavaScript language to professional programmers. It is a small language. If you are familiar with other programming

This article mainly introduces the difference between Null and Undefined in JavaScript. This article provides multiple code instances to explain the differences between them, you can refer to the following two primitive types in JavaScript: Null and

JavaScript basic syntax1. OperatorsThe operator is a series of symbols that complete the operation, which has seven classes:Assignment operators (=,+=,-=,*=,/=,%=,>=,|=,&=), arithmetic operators (+,-, *,/,++,--,%), Comparison operators (>,=,==,== =,!