How do I get console input in spidermonkey JavaScript?

Question

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.

score 58 · Accepted Answer · edited Jan 09 '21 at 13:49

58

Good old readline();.

See MDN (archive).

edited Jan 09 '21 at 13:49

Aryan Beezadhur

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answered Jun 25 '10 at 19:21

MooGoo

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I can't seem to use when using node.js .. Any idea ? – eran otzap Dec 10 '14 at 23:05
1

See the answer to this question: http://stackoverflow.com/questions/26683734/how-can-i-take-console-input-from-a-user-in-node-js – deltaray Jan 29 '17 at 12:24

score 19 · Answer 2 · answered Jul 20 '16 at 06:30

19

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')

answered Jul 20 '16 at 06:30

Zaz

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` var x = readline(); ^ TypeError: readline is not a function ` after adding require at the top of the file – fIwJlxSzApHEZIl Nov 13 '17 at 23:20
1

Also had the same problem. – Devin Haslam Jan 04 '18 at 23:15
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That's weirder than ever. – Machado Sep 26 '18 at 03:27
2

readline does not work the same in node. you need something like this: const readline = require('readline').createInterface({ input: process.stdin, output: process.stdout }) readline.question("what's your name? ", name => { console.log(`Hello ${name}`); readline.close(); }); – kDar Jan 06 '20 at 15:36
1

@kDar I prefer to do name => { readline.close(); console.log(name); } In my case, your version doesn't show input while typing. Anyway, thanks for your comment – Marco M. von Hagen Jul 18 '20 at 15:43

Keyvan · Answer 3 · 2019-06-24T22:55:14.883

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

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

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.

ArcherL · Answer 4 · 2020-09-10T13:23:49.163

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.

score 0 · Answer 5 · answered Mar 29 '22 at 16:54

Node.js has built-in readline module.

one example:

const readline = require('readline')
const rl = readline.createInterface({
   input: process.stdin,
   output: process.stdout,
});
rl.question(`Are you sure? (yes/no): `, async answer => {
   if (answer.toLocaleLowerCase() === 'yes') {
     console.log('processing...');
   }
   else {
     console.log('aborting...');
   }
});

How do I get console input in spidermonkey JavaScript?

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