Why pointers are needed in Go - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a pointer to an integer variable.

Go

var x int = 10
var p [1] = &x

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

A*int

Bint

C&int

Dpointer

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'int' instead of '*int' for pointer type.

Using '&int' which is invalid syntax.

In Go, a pointer to an int is declared as *int. The & operator gets the address of x.

2fill in blank

medium

Complete the code to change the value of x using its pointer p.

Go

var x int = 5
var p *int = &x
*p [1] 20
fmt.Println(x)

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A==

B&

C:=

D=

Attempts:

3 left

💡 Hint

Common Mistakes

Using '==' which is a comparison, not assignment.

Using ':=' which declares a new variable.

To change the value pointed to by p, use the assignment operator = with *p.

3fill in blank

hard

Fix the error in the code to correctly swap two integers using pointers.

Go

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

x, y := 1, 2
swap(&x, &y)
fmt.Println(x, y)

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

Apointer

B*

Cref

D&

Attempts:

3 left

💡 Hint

Common Mistakes

Using '&' which is the address operator, not a type.

Using 'ref' or 'pointer' which are not Go types.

The function parameters must be pointers to int, declared as *int, to modify the original variables.

4fill in blank

hard

Fill both blanks to correctly swap values of two integers using pointers.

Go

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

x, y := 3, 4
swap([2]x, &y)
fmt.Println(x, y)

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

A*

B&

Cref

Dpointer

Attempts:

3 left

💡 Hint

Common Mistakes

Passing variables directly instead of their addresses.

Using 'ref' or 'pointer' which are not valid Go types.

The function parameters must be pointers (*int), and the arguments must be addresses (&x, &y).

5fill in blank

hard

Fill all three blanks to create a function that increments an integer value using a pointer.

Go

func increment([1] [2]int) {
    *[3] += 1
}

var num int = 7
increment(&num)
fmt.Println(num)

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

Ap

B*

C&

Dptr

Attempts:

3 left

💡 Hint

Common Mistakes

Using '&' as a type instead of '*'.

Using different names for parameter and dereference.

The function parameter is a pointer named p of type *int. Inside, dereference p with *p to increment the value.