Home Web Front-end JS Tutorial Introduction to object conversion functions toString() and valueOf()

Introduction to object conversion functions toString() and valueOf()

May 25, 2017 pm 02:49 PM
javascript object tostring() valueof() conversion function

In JavaScript, the operation of converting object to boolean is very simple: all objects are true after being converted to boolean; even objects such as new Boolean(false) are still true after being converted to boolean.

Copy code The code is as follows:

var x = new Boolean(false);if(x){  console.log("x is true");}
Copy after login

When converting object to string or number, JavaScript will call two conversions of object Functions: toString() and valueOf().

toString()

The toString() function is to return the string representation of object. The default toString() method of object in JavaScript returns a string "[object Object]". When defining a class, you can implement the new toString() method to return more readable results. JavaScript defines a more readable toString() method for array objects, function objects, regular expression objects, and Date date objects:

1.array’s toString() method will return comma-separated Array members. For example, [1,2,3].toString() will return the string "1,2,3".

2. The toString() method of function will return the text definition of the function. For example, (function(x){return x*2;}).toString() will return the string "function(x){return x*2;}".

3.RegExp’s toString() method is similar to function’s toString() method and will return the text definition of the regular expression. For example, /d /g.toString() will return the string "/\d /g".

4.Date’s toString() method will return a readable date and time string.

valueOf()

The valueOf() function is to return the numerical representation of the object. The default valueOf() method of object in JavaScript will return the object itself. Like toString(), you can implement a new valueOf() method when defining a class to return the desired result. JavaScript defines a more readable valueOf() method for the Date object:

The valueOf() method of Date will return a value, which is the time difference between the Date object and 0:00 on January 1, 1970 (in milliseconds).

Related recommendations]

1. Detailed explanation of valueOf method examples in java

2. Between valueOf and toString, (String) in Java The difference between

3. Usage of tostring() and valueof() and the difference between the two_

4.valueOf function and toString In-depth understanding of the method

5. The difference between valueOf, parseInt, and toString in Java

6. Using the toString() method to return the time is String

Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

How to implement an online speech recognition system using WebSocket and JavaScript How to implement an online speech recognition system using WebSocket and JavaScript Dec 17, 2023 pm 02:54 PM

How to use WebSocket and JavaScript to implement an online speech recognition system Introduction: With the continuous development of technology, speech recognition technology has become an important part of the field of artificial intelligence. The online speech recognition system based on WebSocket and JavaScript has the characteristics of low latency, real-time and cross-platform, and has become a widely used solution. This article will introduce how to use WebSocket and JavaScript to implement an online speech recognition system.

WebSocket and JavaScript: key technologies for implementing real-time monitoring systems WebSocket and JavaScript: key technologies for implementing real-time monitoring systems Dec 17, 2023 pm 05:30 PM

WebSocket and JavaScript: Key technologies for realizing real-time monitoring systems Introduction: With the rapid development of Internet technology, real-time monitoring systems have been widely used in various fields. One of the key technologies to achieve real-time monitoring is the combination of WebSocket and JavaScript. This article will introduce the application of WebSocket and JavaScript in real-time monitoring systems, give code examples, and explain their implementation principles in detail. 1. WebSocket technology

How to use JavaScript and WebSocket to implement a real-time online ordering system How to use JavaScript and WebSocket to implement a real-time online ordering system Dec 17, 2023 pm 12:09 PM

Introduction to how to use JavaScript and WebSocket to implement a real-time online ordering system: With the popularity of the Internet and the advancement of technology, more and more restaurants have begun to provide online ordering services. In order to implement a real-time online ordering system, we can use JavaScript and WebSocket technology. WebSocket is a full-duplex communication protocol based on the TCP protocol, which can realize real-time two-way communication between the client and the server. In the real-time online ordering system, when the user selects dishes and places an order

How to implement an online reservation system using WebSocket and JavaScript How to implement an online reservation system using WebSocket and JavaScript Dec 17, 2023 am 09:39 AM

How to use WebSocket and JavaScript to implement an online reservation system. In today's digital era, more and more businesses and services need to provide online reservation functions. It is crucial to implement an efficient and real-time online reservation system. This article will introduce how to use WebSocket and JavaScript to implement an online reservation system, and provide specific code examples. 1. What is WebSocket? WebSocket is a full-duplex method on a single TCP connection.

JavaScript and WebSocket: Building an efficient real-time weather forecasting system JavaScript and WebSocket: Building an efficient real-time weather forecasting system Dec 17, 2023 pm 05:13 PM

JavaScript and WebSocket: Building an efficient real-time weather forecast system Introduction: Today, the accuracy of weather forecasts is of great significance to daily life and decision-making. As technology develops, we can provide more accurate and reliable weather forecasts by obtaining weather data in real time. In this article, we will learn how to use JavaScript and WebSocket technology to build an efficient real-time weather forecast system. This article will demonstrate the implementation process through specific code examples. We

Simple JavaScript Tutorial: How to Get HTTP Status Code Simple JavaScript Tutorial: How to Get HTTP Status Code Jan 05, 2024 pm 06:08 PM

JavaScript tutorial: How to get HTTP status code, specific code examples are required. Preface: In web development, data interaction with the server is often involved. When communicating with the server, we often need to obtain the returned HTTP status code to determine whether the operation is successful, and perform corresponding processing based on different status codes. This article will teach you how to use JavaScript to obtain HTTP status codes and provide some practical code examples. Using XMLHttpRequest

How to use insertBefore in javascript How to use insertBefore in javascript Nov 24, 2023 am 11:56 AM

Usage: In JavaScript, the insertBefore() method is used to insert a new node in the DOM tree. This method requires two parameters: the new node to be inserted and the reference node (that is, the node where the new node will be inserted).

JavaScript and WebSocket: Building an efficient real-time image processing system JavaScript and WebSocket: Building an efficient real-time image processing system Dec 17, 2023 am 08:41 AM

JavaScript is a programming language widely used in web development, while WebSocket is a network protocol used for real-time communication. Combining the powerful functions of the two, we can create an efficient real-time image processing system. This article will introduce how to implement this system using JavaScript and WebSocket, and provide specific code examples. First, we need to clarify the requirements and goals of the real-time image processing system. Suppose we have a camera device that can collect real-time image data

See all articles