


Example code details the various ways of outputting data in JavaScript
This article brings you relevant knowledge about javascript. In JavaScript, unlike languages such as Java, it does not have any printing or output methods. There are 4 ways to use it in js To output data, this article will introduce it to you in detail through example code. I hope it will be helpful to you.
[Related recommendations: javascript video tutorial, web front-end】
Preface
In JavaScript, unlike languages such as Java, it does not have any printing or output methods. The following four methods are usually used to output data.
- Use
window.alert()
to pop up the warning box - Use
document.write()
to write the content to HTML In the document - Use
innerHTML
to write to the HTML element - Use
console.log()
to write to the browser console
They are used below to show an example.
window.alert()
Create a new HTML file, and then use VSCode to write the following code.
<!DOCTYPE html> <html> <head> <meta charset="utf-8" /> <meta name="viewport" content="width=device-width, initial-scale=1"> <title>window.alert()</title> </head> <body> <p>弹窗显示</p> <script type="text/javascript"> window.alert("这是一条弹窗测试!"); </script> </body> </html>
Then open the above file with a browser. When it is opened, the following pop-up window will be displayed. After clicking OK, the pop-up window will close and the content will be displayed on the web page.
document.write()
<!DOCTYPE html> <html> <head> <meta charset="utf-8" /> <meta name="viewport" content="width=device-width, initial-scale=1"> <title>document.write()</title> </head> <body> <p>写入 HTML 文档</p> <script type="text/javascript"> document.write(Date()); </script> </body> </html>
After creating a new HTML file and writing the above content, the browser will open and the page will display the following content, as you can see Using document.write()
to write the current time is successful. However, it should be noted that if document.write()
is loaded at the same time as other content before the content is loaded, it can be displayed together with other content. However, if document.write()
is executed after the page content has been loaded, all the previously loaded content will be overwritten by the written content.
<!DOCTYPE html> <html> <head> <meta charset="utf-8" /> <meta name="viewport" content="width=device-width, initial-scale=1"> <title>document.write()</title> </head> <body> <p>写入 HTML 文档</p> <button onclick="showDate()">展示时间</button> <script type="text/javascript"> function showDate() { document.write(Date()); } </script> </body> </html>
The following is the execution of document.write()
after the page is loaded. Comparison before and after, indicating that it is called after the page is loaded. document.write()
will overwrite the previous page content.
before and after
document.getElementById(id) method, and then you can use
innerHTML to get or insert element content.
<!DOCTYPE html> <html> <head> <meta charset="utf-8" /> <meta name="viewport" content="width=device-width, initial-scale=1"> <title>innerHTML</title> </head> <body> <p id="inner">操纵 HTML 元素</p> <button onclick="changeContext()">点击修改上述内容</button> <script type="text/javascript"> function changeContext() { document.getElementById("inner").innerHTML = "修改后的内容"; } </script> </body> </html>
##console.log()
To use
console.log() method requires our browser to support debugging. Chrome is generally recommended. Then use the F12
shortcut key to open debugging mode and switch to the Console
menu in the debugging window. Because I am using Edge
here, the console is displayed. This choice of browser is mainly based on your own preferences, but Chrome is generally recommended. <div class="code" style="position:relative; padding:0px; margin:0px;"><pre class='brush:php;toolbar:false;'><!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>console.log</title>
</head>
<body>
<p>浏览器调试模式查看</p>
<script type="text/javascript">
var num1 = 11;
var num2 = 10;
console.log(num1 + num2);
</script>
</body>
</html></pre><div class="contentsignin">Copy after login</div></div><p style="text-align:center"><img src="/static/imghw/default1.png" data-src="https://img.php.cn/upload/article/000/000/067/6806f16a46549713b25cac5b5dfcc424-6.png" class="lazy" alt="">Summary</p>
<h2 id="The-above-is-about-the-output-in-JavaScript-although-it-is-not-as-similar-as-Java">The above is about the output in JavaScript, although it is not as similar as Java.</h2>System.out.println( )<p> method to print and output, but using the above 4 methods can basically meet the needs of daily development. <code>
【Related recommendations:
The above is the detailed content of Example code details the various ways of outputting data in JavaScript. For more information, please follow other related articles on the PHP Chinese website!

Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

AI Hentai Generator
Generate AI Hentai for free.

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Hot Topics

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 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 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.

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

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

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

Introduction to the method of obtaining HTTP status code in JavaScript: In front-end development, we often need to deal with the interaction with the back-end interface, and HTTP status code is a very important part of it. Understanding and obtaining HTTP status codes helps us better handle the data returned by the interface. This article will introduce how to use JavaScript to obtain HTTP status codes and provide specific code examples. 1. What is HTTP status code? HTTP status code means that when the browser initiates a request to the server, the service

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).
