Could someone please explain this JavaScript answer?

Question

This was a question in a JavaScript challenge quiz:

What is the output of this code?

var name1 = "John";
var name2 = "Sebastian";
console.log(name1.length + "" + name2.length);

I am thinking the answer would be 13...however the answer was 49. Why? Could someone please explain?

Answer 1

Ah, I see. Thank you!

Answer 2

john = 4
Sebastian = 9

as thy are string so 4+9 = 49
its just string function hope you get it

Answer 3

it is using your value as a string and performing concatenation function