Instance Method

prefix(_:)

Returns a subsequence, up to the specified maximum length, containing the initial elements of the collection.

Declaration

func prefix(_ maxLength: Int) -> Substring

Parameters

maxLength

The maximum number of elements to return. maxLength must be greater than or equal to zero.

Return Value

A subsequence starting at the beginning of this collection with at most maxLength elements.

Discussion

If the maximum length exceeds the number of elements in the collection, the result contains all the elements in the collection.

let numbers = [1, 2, 3, 4, 5]
print(numbers.prefix(2))
// Prints "[1, 2]"
print(numbers.prefix(10))
// Prints "[1, 2, 3, 4, 5]"