Javascript Array find(func)

// given a function that takes a single element as an argument
// returns the first element in the array that satisfies the function
Array.prototype.find = function(func) {
  for(var i in this) {
    if(func(this[i])) return this[i]
  }//from w  w  w.  j  a va 2 s  .  com
  return null
}