node.js - How to prevent float and negative input using Javascript?

Question

I'm using readlineSync.questionInt and I need to prompt a message if the user types float or negative number. I used a limit, but it isn't enough.

var readlineSync = require('readline-sync');
var number_of_people = readlineSync.questionInt('How many people are you going with?', { limit: 0 - 9 });

Answer 1

I would use just question and move your custom login into limit callback. For instance, one idea could be checking if the input is an integer and it is in the range between 0-9:

var readlineSync = require('readline-sync');
var number_of_people = readlineSync.question('How many people are you going with?', {
  limit: function(i) {
    const input = Number(i);
    return  Number.isInteger(input) && input > 0 && input < 10;
}});

You could also make use of regexp; just have your callback return true when the input is valid based on your logic