partition([iterator = Prototype.K[, context]]) -> [TrueArray, FalseArray]

Partitions the elements in two groups: those regarded as true, and those considered false. By default, regular JavaScript boolean equivalence is used, but an iterator can be provided, that computes a boolean representation of the elements.

This is a preferred solution to using both findAll/select and reject: it only loops through the elements once!

The optional context parameter is what the iterator function will be bound to. If used, the this keyword inside the iterator will point to the object given by the argument.


['hello', null, 42, false, true, , 17].partition()
// -> [['hello', 42, true, 17], [null, false, undefined]]

$R(1, 10).partition(function(n) {
  return 0 == n % 2;
// -> [[2, 4, 6, 8, 10], [1, 3, 5, 7, 9]]