Node.js -3 | Reading user input from the command line

Readline module, which comes with the Node.js core reads user input so that you can use it as an interaction.

In this example, the user will tell how many glasses of water he/she drinks each day and we’ll say if it’s healthy enough or not.

In the script.js file, require the module like:

var rl = require("readline");

Create the prompts variable:

var prompts = rl.createInterface(process.stdin, process.stdout);

Request user input with a question:

prompts.question("How many glass of water do you drink each day?", function (glasses) {
	var message = "";
	if (glasses > 5) {
		message = "Great! Water is the key of a healthy life.";
	} else {
		message = "Are you drinking just " + glasses + " glass of water? You should drink at least " + (6 - glasses) + " more.";
	}
	console.log(message);
	process.exit();
});

Output will be like:

> node script.js
> How many glass of water do you drink each day?
> 5
> Are you drinking just 5 glass of water? You should drink at least 1 more.
> node script.js
> How many glass of water do you drink each day?
> 7
> Great! Water is the key of a healthy life.