How to check if a prompt is a number?

Question

Help

Answer 1

Typeof return value of prompt is always string.

Answer 2

// chech.min.js
alert(!isNaN(prompt('Type a number')));

Answer 3

let pro = +prompt('Type a number!, 0); // unary + convert it to a number
if(isNaN(pro)) { // NaN means Not a Number check if it is
alert('It is not a number');
} else {
// Here it is a number
}

Answer 4

To check the typeof prompt first store it's value in a variable or else you could type - console.log(typeof prompt("Value")); But the type of prompt is always a string.

Answer 5

There is the one "grandfather`s method":

input = prompt('Enter a number');
if(Number(input)%1===0) console.log('Number!');
else console.log('String!');

Answer 6

Type of return value of string is always string

const number = '1234';
console.log(number);