Array Slice

 In Swift, an array slice is a portion of an array that refers to a contiguous subsequence of elements in the original array. Array slices provide a way to work with a subset of an array without creating a new copy of the elements. 

To create an array slice in Swift, you can use the following syntax:

let slice = array[startIndex..<endIndex]

where array is the original array, startIndex is the index of the first element to include in the slice, and endIndex is the index of the first element to exclude from the slice. The resulting slice will include all the elements between startIndex (inclusive) and endIndex (exclusive). 

For example, let's say you have an array of integers:

let numbers = [1, 2, 3, 4, 5]

You can create a slice of the first three elements of the array using the following code:

let slice = numbers[0..<3]

This will create a slice containing the elements [1, 2, 3]. Note that the original numbers array is not modified by this operation.

 You can also use the Array constructor to create an array slice from an existing array:

let slice = Array(array[startIndex..<endIndex])

This will create a new array containing the elements in the specified slice of the original array.

Array slices can be useful for working with portions of an array, particularly when you need to pass a subset of the array to a function or method. They can also be used to modify a portion of the original array without affecting the rest of the elements.