Javascript custom functions with string

Question

Today i was asked question in interview. when i call 'hello'.replicate(3) it should print 'hellohellohello'

please help if anyone has answer to this

// 'hello'.replicate(3)
//output > 'hellohellohello'


function replicate(num){
  for(i=0; i<3; i++){
    
  }
}

Show your effort? Also don't modify builtin object (string) behavior. — user202729, Jan 30 '18 at 02:10
'helo' a string and attach function to it and get output. i never did this before and got stuck here — Jay, Jan 30 '18 at 02:13
[Dupe](https://stackoverflow.com/questions/8392035/javascript-add-method-to-string-class). You didn't research before asking, downvote. — user202729, Jan 30 '18 at 02:14

score 2 · Accepted Answer · answered Jan 30 '18 at 02:21

A JavaScript string will inherit functions from its prototype, so you need to add the function to the string prototype. For example:

String.prototype.replicate = function (n) {
  var replicatedString = '';

  for (var i = 0; i < n; i++) {
    replicatedString += this;
  }

  return replicatedString;
};

Javascript custom functions with string

1 Answers1