Javascript String elipse(x)

"use-strict"//from  w w w.j  av a  2  s .c  o m

/*
This was a technical question that came up in an interview.
I got it half correct, but forgot to include the prototype portion.
*/

/*
Question:
 How would you write code to elipse (or truncate) a string?

Setup:
 let name ="1234567890"

 name.elipse(8);

 elipse {
  ...
 }

My Initial Anser:
 function elipse(x) {
  return this.substring(0, x);
 }

*/

// Correct Answer
let name = "1234567890";

String.prototype.elipse = function (x) {
 return this.substring(0, x);
}

console.log(name.elipse(8));