Returning from prompt.get

Question

I'm currently using the prompt package in Node to get user input on the command line, however, I would like to return a variable from prompt.get - how would I store the return variable/where can I access it from? I'm relatively new to Node.

const prompt = require('prompt');

prompt.start();
prompt.get(['num'], function (err: any, result: any) {
    if (err) { return Error(err); }
    if(result.num > 0) {
        return "Positive";
    }
    else {
        return "Negative";
    }
});

Cheers!

Answer 1

You could initialize the variable outside the callback, and then set the variable inside of the callback:

let value;

prompt.get(['num'], function (err: any, result: any) {
    if (err) { return Error(err); }

    value = result > 0 ? "Positive" : "Negative";
});

But the problem is the value will be empty until it's done, so if you try to call it right after, it will be empty.

let value;

prompt.get(['num'], function (err: any, result: any) {
    if (err) { return Error(err); }

    value = result > 0 ? "Positive" : "Negative";
});

console.log(value); // => undefined

The package also supports promises though, so you can just use await, as shown on their readme:

(async () => {
    const { num } = await prompt.get(['num']);
})();

You should notice the anonymous self executing async function, that's because await only works inside of async functions (technically not needed after node v15 & while using modules).