What is a better way to write "array.length - 1" in JavaScript?

Question

Instead of using array.length-1 to get the largest index of an array can you do some thing like this array.largestIndex?

Answer 1

You can use JS getter to do this.

Object.defineProperty(Array.prototype, 'largestIndex', {
   get: function () {
      return (this.length == 0) ? null : this.length - 1
   }
});