Why it alert's string when you enter a number.?

Question

https://code.sololearn.com/WTPojwGulhn4/?ref=app

Answer 1

It's the default return type from a prompt.
I'd suggest to use the isNaN statement to test (is Not a Number), which understands if the value of the variable is not usable as a number. Just add the not logical operator (!) and you've done.

function a() {
var b = prompt("Enter s.th");

var type;

if (!isNaN(b))
type = 'It is a Number!';
else
type = 'It is a String!';

alert(type);
}

a()

Answer 2

because the default value of a type of data received in a prompt is string

Answer 3

Obviously we can reverse the code to be more straightforward:

if (isNaN(b))
type = 'It is a String!';
else
type = 'It is a Number!';

Answer 4

Yes I underestood thanks

Answer 5

Ok thanks

Answer 6

I have a question you wrote
if(!isNaN(b)){
type="it's a number"
}
it means if b is not a number

Answer 7

Please note the ! before the isNaN statement, that means it will reverse the value of isNaN(b).

// User wrote 7
isNaN(b) = false
!isNaN(b) = true

//User wrote “hello”
isNaN(b) = true
!isNaN(b) = false

Answer 8

Ok