Home Web Front-end JS Tutorial A brief discussion on scope issues in Nodejs

A brief discussion on scope issues in Nodejs

Jan 04, 2017 pm 04:26 PM

About debugging

When we only focus on the front end, we are used to F12, which will bring us a sense of security and comfort.

But when we use NodeJs to develop the backend, I think the nightmare is coming.

But don’t worry, debugging NodeJs is very inconvenient! Definitely.

But fortunately, we have ## node-inspector ## to help us solve part of the debugging problems, but it is still a bit inadequate for NodeJs, which has strong asynchronous capabilities.

node-inspector

Install node-inspector

Still install node-inspector globally through npm

npm install -g node-inspector

Test code

//event.js
var events = require('events');
var util = require('util');
function tianxiasan(name){
 this.name = name;
 events.EventEmitter.call(this);
}
util.inherits(Restaurant, events.EventEmitter);
//定义角色
var restaurant = new tianxiasan('奕剑');
Copy after login

This is the code we want to debug

Start node-inspector

Start node-inspector first

C:\Users\Administrator>node-inspector
Node Inspector v0.12.8
Visit http://127.0.0.1:8080/?port=5858 to start debugging.
Copy after login

Okay , started successfully.

Start the debug mode of nodejs

Reopen a terminal, and then start the debug function provided by nodejs

C:\Users\Administrator\Desktop>node --debug-brk event.js
Debugger listening on port 5858
Copy after login

--debug-brk means to use the debug mode to start the event .js and put a breakpoint on the first line.

View the effect

In this way, the two programs communicate through socket. We can debug NodeJs in the Google Developer Tools in our properties.

A brief discussion on scope issues in Nodejs

What a familiar interface, the debugging process below is similar to Js debugging.

The above is the entire content of this article. I hope that the content of this article can bring some help to everyone's study or work. I also hope to support the PHP Chinese website!

For more articles on scope issues in Nodejs, please pay attention to the PHP Chinese website!


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)

Hot Topics

Java Tutorial
1659
14
PHP Tutorial
1258
29
C# Tutorial
1232
24
Demystifying JavaScript: What It Does and Why It Matters Demystifying JavaScript: What It Does and Why It Matters Apr 09, 2025 am 12:07 AM

JavaScript is the cornerstone of modern web development, and its main functions include event-driven programming, dynamic content generation and asynchronous programming. 1) Event-driven programming allows web pages to change dynamically according to user operations. 2) Dynamic content generation allows page content to be adjusted according to conditions. 3) Asynchronous programming ensures that the user interface is not blocked. JavaScript is widely used in web interaction, single-page application and server-side development, greatly improving the flexibility of user experience and cross-platform development.

The Evolution of JavaScript: Current Trends and Future Prospects The Evolution of JavaScript: Current Trends and Future Prospects Apr 10, 2025 am 09:33 AM

The latest trends in JavaScript include the rise of TypeScript, the popularity of modern frameworks and libraries, and the application of WebAssembly. Future prospects cover more powerful type systems, the development of server-side JavaScript, the expansion of artificial intelligence and machine learning, and the potential of IoT and edge computing.

JavaScript Engines: Comparing Implementations JavaScript Engines: Comparing Implementations Apr 13, 2025 am 12:05 AM

Different 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.

JavaScript: Exploring the Versatility of a Web Language JavaScript: Exploring the Versatility of a Web Language Apr 11, 2025 am 12:01 AM

JavaScript 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.

Python vs. JavaScript: The Learning Curve and Ease of Use Python vs. JavaScript: The Learning Curve and Ease of Use Apr 16, 2025 am 12:12 AM

Python 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.

How to Build a Multi-Tenant SaaS Application with Next.js (Frontend Integration) How to Build a Multi-Tenant SaaS Application with Next.js (Frontend Integration) Apr 11, 2025 am 08:22 AM

This 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

From C/C   to JavaScript: How It All Works From C/C to JavaScript: How It All Works Apr 14, 2025 am 12:05 AM

The 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.

Building a Multi-Tenant SaaS Application with Next.js (Backend Integration) Building a Multi-Tenant SaaS Application with Next.js (Backend Integration) Apr 11, 2025 am 08:23 AM

I 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

See all articles