Is it possible for a variable len to show a smaller length than the actual size of an array or slice?

In Go, the variable len for an array or slice always reflects the current length returned by the built-in len() function.

• For an array, len is always equal to the size of the array and does not change.
• For a slice, len shows the number of elements in the slice, which can be less than or equal to the capacity of the slice.

A situation where len is less than the actual size of the array is impossible, as len for an array is fixed and equal to its size.

For a slice, the length can be less than the capacity but not greater than the actual number of elements accessible by index.

Example:

arr := [5]int{1,2,3,4,5}
fmt.Println(len(arr)) // 5

slice := arr[1:3]
fmt.Println(len(slice)) // 2
fmt.Println(cap(slice)) // 4

Here, the length of the slice is 2, although the capacity is 4. But the length cannot be greater than the actual size of the slice.