[javascript] How do I get console input in javascript?

I'm currently using spidermonkey to run my JavaScript code. I'm wondering if there's a function to get input from the console similar to how Python does this:

var = raw_input()  

Or in C++:

std::cin >> var;

I've looked around and all I've found so far is how to get input from the browser using the prompt() and confirm() functions.

This question is related to javascript input console spidermonkey

The answer is


Good old readline();.

See MDN (archive).


As you mentioned, prompt works for browsers all the way back to IE:

var answer = prompt('question', 'defaultAnswer');

prompt in IE

For Node.js > v7.6, you can use console-read-write, which is a wrapper around the low-level readline module:

const io = require('console-read-write');

async function main() {
  // Simple readline scenario
  io.write('I will echo whatever you write!');
  io.write(await io.read());

  // Simple question scenario
  io.write(`hello ${await io.ask('Who are you?')}!`);

  // Since you are not blocking the IO, you can go wild with while loops!
  let saidHi = false;
  while (!saidHi) {
    io.write('Say hi or I will repeat...');
    saidHi = await io.read() === 'hi';
  }

  io.write('Thanks! Now you may leave.');
}

main();
// I will echo whatever you write!
// > ok
// ok
// Who are you? someone
// hello someone!
// Say hi or I will repeat...
// > no
// Say hi or I will repeat...
// > ok
// Say hi or I will repeat...
// > hi
// Thanks! Now you may leave.

Disclosure I'm author and maintainer of console-read-write

For SpiderMonkey, simple readline as suggested by @MooGoo and @Zaz.


In plain JavaScript, simply use response = readline() after printing a prompt.

In Node.js, you'll need to use the readline module: const readline = require('readline')


You can try something like process.argv, that is if you are using node.js to run the program.
console.log(process.argv) => Would print an array containing

[                                                                                                                                                                                          
  '/usr/bin/node',                                                                                                                                                                         
  '/home/user/path/filename.js',                                                                                                                                            
  'your_input'                                                                                                                                                                                   
]

You get the user provided input via array index, i.e., console.log(process.argv[3]) This should provide you with the input which you can store.


Example:

var somevariable = process.argv[3]; // input one
var somevariable2 = process.argv[4]; // input two

console.log(somevariable);
console.log(somevariable2);

If you are building a command-line program then the npm package yargs would be really helpful.


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