Passing values vs pointers in Go - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a function that takes an integer value.

Go

func increment([1] int) int {
    return [1] + 1
}

Drag options to blanks, or click blank then click option'

Anum

B*num

C&num

Dval

Attempts:

3 left

💡 Hint

Common Mistakes

Using * or & in the parameter name when passing by value.

The function parameter should be a simple variable name without pointer symbols to pass by value.

2fill in blank

medium

Complete the code to declare a function that takes a pointer to an integer.

Go

func incrementPointer([1] *int) {
    *[1] = *[1] + 1
}

Drag options to blanks, or click blank then click option'

Aptr

Bval

Cnum

Dx

Attempts:

3 left

💡 Hint

Common Mistakes

Using inconsistent variable names inside the function.

The parameter name can be any valid identifier; here, 'num' is used consistently.

3fill in blank

hard

Fix the error in the code to correctly modify the original variable using a pointer.

Go

func main() {
    x := 5
    incrementPointer([1]x)
    fmt.Println(x)
}

Drag options to blanks, or click blank then click option'

Ax

B&

Attempts:

3 left

💡 Hint

Common Mistakes

Passing the variable without & when a pointer is expected.

To pass the address of x, use the & operator before x.

4fill in blank

hard

Fill both blanks to create a function that swaps two integers using pointers.

Go

func swap([1] *int, [2] *int) {
    temp := *a
    *a = *b
    *b = temp
}

Drag options to blanks, or click blank then click option'

Aa

Bb

Cx

Dy

Attempts:

3 left

💡 Hint

Common Mistakes

Using parameter names that don't match the function body.

The function parameters should be pointer variables named 'a' and 'b' to match the function body.

5fill in blank

hard

Fill all three blanks to call the swap function correctly in main.

Go

func main() {
    x, y := 3, 4
    swap([1][2], [3]y)
    fmt.Println(x, y)
}

Drag options to blanks, or click blank then click option'

A&

Bx

C,

D*

Attempts:

3 left

💡 Hint

Common Mistakes

Passing values instead of pointers to swap.

Missing the comma between arguments.

Use &x and &y to pass pointers to the swap function. The comma separates arguments.