nth
nth<
T>(iterable,index):T|undefined
Defined in: packages/core/src/iterable/nth.ts:21
Returns the element at index, or undefined when the iterable is shorter
than that.
T cannot itself include undefined, so the absent case is never ambiguous.
Only counts forward. Array.prototype.at’s negative index would mean
buffering the whole tail to know where the end is, so it is rejected rather
than paid for silently — last covers the -1 case in O(1) for an array.
Time complexity: O(index). The iterator is closed as soon as the element is reached, without draining the rest.
Type Parameters
Section titled “Type Parameters”T extends DefinedValue
Parameters
Section titled “Parameters”iterable
Section titled “iterable”Iterable<T>
The iterable to read from.
number
The zero-based position to read. Must be a non-negative integer.
Returns
Section titled “Returns”T | undefined
The element at index, or undefined if there is none.
Throws
Section titled “Throws”If index is not a non-negative integer.