Common pointer use cases in Go - Mini Project: Build & Apply

Common pointer use cases

📖 Scenario: You are learning how pointers work in Go. Pointers let you directly change values stored in memory. This is useful when you want to update data inside functions or share data efficiently.

🎯 Goal: Build a simple Go program that uses pointers to update a variable's value, swap two numbers, and modify a struct field.

📋 What You'll Learn

Create an integer variable and a pointer to it

Create a function that uses a pointer to update an integer value

Create a function that swaps two integers using pointers

Create a struct and a function that modifies its field using a pointer

💡 Why This Matters

🌍 Real World

Pointers are used in Go to efficiently update data, manage memory, and work with complex data structures like linked lists or trees.

💼 Career

Understanding pointers is important for Go developers working on performance-critical applications, system programming, or backend services.

1

Create an integer variable and a pointer to it

Create an integer variable called num with value 10. Then create a pointer variable called ptr that points to num.

Go

# Create an integer variable called num with value 10
# Create a pointer variable called ptr that points to num

Hint

Use & to get the address of a variable.

2

Create a function to update an integer value using a pointer

Add a function called updateValue that takes a pointer to an integer *int and sets the value it points to 20. Call updateValue in main passing ptr.

Go

package main

import "fmt"

func main() {
    num := 10
    ptr := &num

    // Call updateValue with ptr

}

// Create updateValue function here

Hint

Use *p = 20 to change the value at the pointer.

3

Create a function to swap two integers using pointers

Add a function called swap that takes two pointers to integers *int and swaps the values they point to. In main, create two integers a = 5 and b = 10, then call swap passing pointers to a and b.

Go

package main

import "fmt"

func updateValue(p *int) {
    *p = 20
}

func main() {
    num := 10
    ptr := &num

    updateValue(ptr)

    // Create variables a and b
    // Call swap with pointers to a and b
}

// Create swap function here

Hint

Use a temporary variable to swap values pointed by the pointers.

4

Create a struct and modify its field using a pointer

Define a struct type called Person with a field age of type int. Create a function called increaseAge that takes a pointer to Person and increases the age by 1. In main, create a Person variable with age = 30, then call increaseAge passing its pointer. Finally, print the updated age using fmt.Println.

Go

package main

import "fmt"

func updateValue(p *int) {
    *p = 20
}

func swap(x *int, y *int) {
    temp := *x
    *x = *y
    *y = temp
}

func main() {
    num := 10
    ptr := &num

    updateValue(ptr)

    a := 5
    b := 10
    swap(&a, &b)

    // Create a Person variable with age 30
    // Call increaseAge with pointer to Person
    // Print the updated age
}

// Define Person struct
// Define increaseAge function

Hint

Use p.age += 1 to increase the age field through the pointer.