How do I get console input in javascript?
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30-09-2019 - |
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.
Solution
Good old readline();
See MDN docs: https://developer.mozilla.org/en-US/docs/Mozilla/Projects/SpiderMonkey/Introduction_to_the_JavaScript_shell#readline.28.29
OTHER TIPS
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')
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.