Question

I have the following function:

var chr = function(X) {
   return String.fromCharCode(X)
}

But I would like to use i.chr() instead of chr(i).

Q: How do I add chr() to the number prototype?

Answer 1

if (!Number.prototype.hasOwnProperty('chr')) {
   Number.prototype.chr = function() {
      return String.fromCharCode(this);
   };
}

To use this the number must be in a variable or wrapped in parentheses. Be aware that converting a scalar number to a Number object (called boxing) has an overhead. If you are doing the conversion repeatedly on the same value, you’ll want to explicitly convert it to an object first with Number().

Note that simply doing String.fromCharCode might be easier or more clear in some situations.