How to extract initial elements from an array or data slice in your programming language?

In Go, to extract the initial elements from a slice, the slicing operation is used. For example, to get the first n elements of a slice arr, you can write:

firstN := arr[:n]

If arr is an array, it must first be converted to a slice, for example:

arr := [5]int{1, 2, 3, 4, 5}
firstThree := arr[:3] // slice of the first three elements

It is important that n does not exceed the length of the slice or array, otherwise a runtime panic will occur.