What will the program output? func a() { x := []int{} x = append(x, 0) x = append(x, 1) x = append(x, 2) y := append(x, 3) z := append(x, 4) fmt.Println(y, z) } func main() { a() }

The program will output:

[0 1 2 3] [0 1 2 4]

Explanation:

• Initially, x is an empty slice.
• Elements 0, 1, 2 are added to x.
• y := append(x, 3) adds 3 to the slice x. If the capacity of the slice is sufficient, y and x will refer to the same underlying array, but the length of y will be greater.
• z := append(x, 4) also adds an element, but since y has already modified the array, adding 4 to z creates a new array to avoid overwriting.

Thus, y contains [0 1 2 3], and z contains [0 1 2 4].

Example for clarity:

func a() {
    x := []int{}
    x = append(x, 0)
    x = append(x, 1)
    x = append(x, 2)
    y := append(x, 3)
    z := append(x, 4)
    fmt.Println(y, z)
}

func main() {
    a()
}