Web Front-endJS TutorialJavaScript attribute prototype for adding properties and methods to objectsJavaScript attribute prototype for adding properties and methods to objects
Definition and Usage
The prototype attribute gives you the ability to add properties and methods to an object.
Syntax
object.prototype.name=value
Example
In this example, we will show how to use the prototype attribute to add properties to an object:
<script type="text/javascript">
function employee(name,job,born)
{
this.name=name;
this.job=job;
this.born=born;
}
var bill=new employee("Bill Gates","Engineer",1985);employee.prototype.salary=null;bill.salary=20000;
document.write(bill.salary);
</script>Output:
20000
The role of the prototype attribute
In order to solve the shortcoming that attributes cannot be shared between object instances of the constructor, js provides the prototype attribute.
Every data type in js is an object (except null and undefined), and each object inherits from another object. The latter is called a "prototype" object, and only null Except, it doesn't have its own prototype object.
All properties and methods on the prototype object will be shared by the object instance.
When an object instance is generated through a constructor, the prototype of the object instance will point to the prototype attribute of the constructor. Each constructor has a prototype attribute, which is the prototype object of the object instance.
function Person(name,height){
this.name=name;
this.height=height;
}
Person.prototype.hobby=function(){
return 'watching movies';
}
var boy=new Person('keith',180);
var girl=new Person('rascal',153);
console.log(boy.name); //'keith'
console.log(girl.name); //'rascal'
console.log(boy.hobby===girl.hobby); //trueIn the above code, if the hobby method is placed on the prototype object, then both instance objects share the same method. What I hope everyone can understand is that for constructors, prototype is the attribute of the constructor; for object instances, prototype is the prototype object of the object instance. So prototype is both an attribute and an object.
The above is the detailed content of JavaScript attribute prototype for adding properties and methods to objects. For more information, please follow other related articles on the PHP Chinese website!
Python vs. JavaScript: The Learning Curve and Ease of UseApr 16, 2025 am 12:12 AMPython is more suitable for beginners, with a smooth learning curve and concise syntax; JavaScript is suitable for front-end development, with a steep learning curve and flexible syntax. 1. Python syntax is intuitive and suitable for data science and back-end development. 2. JavaScript is flexible and widely used in front-end and server-side programming.
Python vs. JavaScript: Community, Libraries, and ResourcesApr 15, 2025 am 12:16 AMPython and JavaScript have their own advantages and disadvantages in terms of community, libraries and resources. 1) The Python community is friendly and suitable for beginners, but the front-end development resources are not as rich as JavaScript. 2) Python is powerful in data science and machine learning libraries, while JavaScript is better in front-end development libraries and frameworks. 3) Both have rich learning resources, but Python is suitable for starting with official documents, while JavaScript is better with MDNWebDocs. The choice should be based on project needs and personal interests.
From C/C to JavaScript: How It All WorksApr 14, 2025 am 12:05 AMThe shift from C/C to JavaScript requires adapting to dynamic typing, garbage collection and asynchronous programming. 1) C/C is a statically typed language that requires manual memory management, while JavaScript is dynamically typed and garbage collection is automatically processed. 2) C/C needs to be compiled into machine code, while JavaScript is an interpreted language. 3) JavaScript introduces concepts such as closures, prototype chains and Promise, which enhances flexibility and asynchronous programming capabilities.
JavaScript Engines: Comparing ImplementationsApr 13, 2025 am 12:05 AMDifferent JavaScript engines have different effects when parsing and executing JavaScript code, because the implementation principles and optimization strategies of each engine differ. 1. Lexical analysis: convert source code into lexical unit. 2. Grammar analysis: Generate an abstract syntax tree. 3. Optimization and compilation: Generate machine code through the JIT compiler. 4. Execute: Run the machine code. V8 engine optimizes through instant compilation and hidden class, SpiderMonkey uses a type inference system, resulting in different performance performance on the same code.
Beyond the Browser: JavaScript in the Real WorldApr 12, 2025 am 12:06 AMJavaScript's applications in the real world include server-side programming, mobile application development and Internet of Things control: 1. Server-side programming is realized through Node.js, suitable for high concurrent request processing. 2. Mobile application development is carried out through ReactNative and supports cross-platform deployment. 3. Used for IoT device control through Johnny-Five library, suitable for hardware interaction.
Building a Multi-Tenant SaaS Application with Next.js (Backend Integration)Apr 11, 2025 am 08:23 AMI built a functional multi-tenant SaaS application (an EdTech app) with your everyday tech tool and you can do the same. First, what’s a multi-tenant SaaS application? Multi-tenant SaaS applications let you serve multiple customers from a sing
How to Build a Multi-Tenant SaaS Application with Next.js (Frontend Integration)Apr 11, 2025 am 08:22 AMThis article demonstrates frontend integration with a backend secured by Permit, building a functional EdTech SaaS application using Next.js. The frontend fetches user permissions to control UI visibility and ensures API requests adhere to role-base
JavaScript: Exploring the Versatility of a Web LanguageApr 11, 2025 am 12:01 AMJavaScript is the core language of modern web development and is widely used for its diversity and flexibility. 1) Front-end development: build dynamic web pages and single-page applications through DOM operations and modern frameworks (such as React, Vue.js, Angular). 2) Server-side development: Node.js uses a non-blocking I/O model to handle high concurrency and real-time applications. 3) Mobile and desktop application development: cross-platform development is realized through ReactNative and Electron to improve development efficiency.
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
mPDF
mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),
SAP NetWeaver Server Adapter for Eclipse
Integrate Eclipse with SAP NetWeaver application server.
WebStorm Mac version
Useful JavaScript development tools
MinGW - Minimalist GNU for Windows
This project is in the process of being migrated to osdn.net/projects/mingw, you can continue to follow us there. MinGW: A native Windows port of the GNU Compiler Collection (GCC), freely distributable import libraries and header files for building native Windows applications; includes extensions to the MSVC runtime to support C99 functionality. All MinGW software can run on 64-bit Windows platforms.
VSCode Windows 64-bit Download
A free and powerful IDE editor launched by Microsoft
