javascript - How to take two consecutive input with the readline module of node.js?

Question

I am creating a program to take input of two numbers from the command line and then showing there sum in node.js. I am using readline module to take stdin. Below is my code.

const readline = require('readline');

const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout
});

const r2 = readline.createInterface({
    input: process.stdin,
    output: process.stdout
});

rl.question('Please enter the first number', (answer1) => {
    r2.question('Please enter the second number', (answer2) => {
        var result = (+answer1) + (+answer2);
        console.log(`The sum of above two numbers is ${result}`);
    });
    rl.close();
});

This program just show me "Please enter the first number" and when i enter a number like 5, it takes 5 for second input also and shows the answer 10

It don't ask second question at all. Please check this and tell me what is the problem. And if there is any better way to take multiple input please tell that.

I am a novice user in node.js

Answer 1

Nested code/callback are terrible to read and maintain, here's a more elegant way to use Promise for asking multiple questions

node 8+

'use strict'

const readline = require('readline')

const rl = readline.createInterface({
  input: process.stdin,
  output: process.stdout
})

const question1 = () => {
  return new Promise((resolve, reject) => {
    rl.question('q1 What do you think of Node.js? ', (answer) => {
      console.log(`Thank you for your valuable feedback: ${answer}`)
      resolve()
    })
  })
}

const question2 = () => {
  return new Promise((resolve, reject) => {
    rl.question('q2 What do you think of Node.js? ', (answer) => {
      console.log(`Thank you for your valuable feedback: ${answer}`)
      resolve()
    })
  })
}

const main = async () => {
  await question1()
  await question2()
  rl.close()
}

main()