Creating a slice from an array

Many functions will accept slices and not arrays. If you have an array of values and need to pass it to a function that wants a slice, you need to create a slice from an array. This is easy and efficient. Creating a slice from an array is a constant-time operation.

How to do it...

Use the [:] notation to create a slice from the array. The slice will have the array as its underlying storage:

arr := [...]int{0, 1, 2, 3, 4, 5}
slice := arr[:] // slice has all elements of arr
slice[2]=10
// Here, arr = [...]int{0,1,10,3, 4,5}
// len(slice) = 6
// cap(slice) = 6

You can create a slice pointing to a section of the array:

slice2 := arr[1:3]
// Here, slice2 = {1,10}
// len(slice2) = 2
// cap(slice2) = 5

You can slice an existing slice. The bounds of the slicing operation are determined by the capacity of the original slice:

slice3 := slice2[0:4]
// len(slice3)=4
// cap(slice3)=5
// slice3 = {1,10,3,4}

How it works...

A slice is a data...