"prompt not defined" using node from command line?

Question

I'm trying to run a simple javascript program from the command line and am getting an unexpected error. prompt seems to be a simple javascript command; not sure why it's not defined.

my test.js file:

console.log("I will now ask you for your name.");
var name = prompt("Enter your name");
console.log("Hello ".concat(name, ". How are you"));

I'm running it like this:

C:\directory\node test.js
I will now ask you for your name.

C:\directory\test.js:2
var name = prompt("Enter your name");

Reference Error: prompt is not defined

You probably want to use readline. window.prompt() is a function that web browsers implement, but it is not a native function in node.js. — user499054
– user499054, Commented Jun 18, 2014 at 17:45
So lets say I simply want to run this code and see the results, what is the best way to do this? My school told us to install node and use that but it seems like that is the wrong way to go about it judging by your responses — user3753598
– user3753598, Commented Jun 18, 2014 at 17:56

Henry · Accepted Answer · 2018-10-07 00:24:14Z

3

you might wanna check this out as well but first run npm install prompt -- save

var prompt = require("prompt");
prompt.start();
console.log("I will now ask you for your name.");
prompt.get(["name"], function(err, res){
console.log("Hello ".concat(res.name, ". How are you"));
});

edited Oct 7, 2018 at 0:24

Henry

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answered Oct 6, 2018 at 17:54

soben360

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1 Comment

Rafael Over a year ago

Node does not implement window.prompt() and using a lib to emulate this is a bad idea. Instead, the OP should use readline.

Paolo Joaquin Zarate Azorsa · Accepted Answer · 2024-01-13 21:51:10Z

“PROMPT” is a JavaScript Function that is available when you are using JS in browsers (Google Chrome, Safari, Microsoft Edge, etc.), and what this allows us to do is take users' inputs.

Now, when running your code outside the browser, Node.js doesn’t have access to this function, so instead, you are going to need to install a Node.js module called “prompt - sync”.

STEPS :

1.- Go to your windows terminal, copy and paste the following command.

npm install prompt-sync   (make sure you have NPM and Node JS installed on your system)

2.- Now, you have to load this module in your JS program, your code should look something like this.

const ps = require("prompt-sync");

const prompt = ps();

console.log("I will now ask you for your name.");

var name = prompt("Enter your name: ");

console.log("Hello ".concat(name, ". How are you?"));

and this will solve the issue👍.

azero0 · Accepted Answer · 2014-06-18 18:24:03Z

2

I think you might be interested in this code :

console.log("I will now ask you for your name.");
process.stdin.setEncoding('utf8');
var name;
process.stdin.on('readable', function() {
    name = process.stdin.read();
    if (name !== null) {
        console.log("Hello ".concat(name, ". How are you"));
        process.exit();
    }
});

this is the node.js way of doing what you need to do. Hope this helps!

answered Jun 18, 2014 at 18:24

azero0

2,3104 gold badges22 silver badges33 bronze badges

Comments

Arron McCrory · Accepted Answer · 2023-11-08 15:09:58Z

1

Node.js does not support prompt out of the box like web browsers do. Node.js does have it's own version of prompt called readline

const readline = require("readline");
let rl = readline.createInterface(process.stdin, process.stdout);
rl.question("What is your age? ", (age) => {
  console.log("Your age is: " + age);
});

Read this article for more information https://www.geeksforgeeks.org/node-js-readline-module/

answered Nov 8, 2023 at 15:09

Arron McCrory

7287 silver badges15 bronze badges

Comments

45 Hakim Mohsin · Accepted Answer · 2025-03-25 06:08:06Z

-1

In Node.js, there’s no built-in prompt() like in browsers. So if you want to take input from the user in the terminal, you need to use packages like prompt-sync. npm install prompt-sync const prompt = require('prompt-sync')(); simple example const name = prompt('What is your name? '); console.log(Hello, ${name}!);

edited Mar 25 at 6:08

answered Nov 5, 2023 at 10:42

45 Hakim Mohsin

11 bronze badge

1 Comment

Community Over a year ago

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