Question

I am a beginner in nodeJS, and I have some questions which I’d like answered.

1. First, when I went to install nodeJS, it was installed with two different command prompts. The first command prompt is blank, and shows “>”. The second command prompt is a windows command prompt, but with the message “Your environment has been set up for using Node.js 0.8.18 (ia32) and NPM”. By entering the code node code.js I am able to start running nodeJS with the second command prompt, but I don’t know how to use the first command prompt that I described above. Could someone please explain to me what the first command prompt is used for?

2. My second question as a beginner in nodeJS is about creating servers. I haven’t gone to deep with what nodeJS can do. But if nodeJS can create a server, then would it be safe to assume that nodeJS can be used to create database software for something like PHP or Python to interact with?

Answer 1

1. The first command prompt is REPL, which means you just enter your command and it evaluates and keeps running. It is like a live console to test some functionality.

2. NodeJS can do many things, its event driven model is a good alternative to similar systems. NodeJS can communicate with database, another computer, or with user. It is just a platform with Javascript programming language. As it is stated on nodejs website, it is “lightweight and efficient, perfect for data-intensive real-time applications that run across distributed devices.”

EDIT: Example Interaction with REPL

$ nodejs
> process.version
'v0.8.18'
> var a = 5;
undefined
> var b = 5
undefined
> a + b
10
> var dns = require("dns");
undefined
> dns.resolve4("www.google.com",function(err,address){console.log(address); })
{ oncomplete: [Function: onanswer] }
> [ '173.194.35.144',
  '173.194.35.145',
  '173.194.35.146',
  '173.194.35.147',
  '173.194.35.148' ]