Creating custom packages in Go - Try It Yourself

Creating custom packages

📖 Scenario: You are building a small Go program that uses a custom package to organize your code better. This is like having a toolbox with different compartments for different tools.

🎯 Goal: Create a custom package named greetings that has a function to return a welcome message. Then use this package in your main program to print the message.

📋 What You'll Learn

Create a package named greetings in a separate file

Inside greetings, write a function WelcomeMessage that returns a string

In the main program, import the greetings package

Call greetings.WelcomeMessage() and print its result

💡 Why This Matters

🌍 Real World

Custom packages help organize code into reusable parts, making programs easier to manage and understand.

💼 Career

Knowing how to create and use packages is essential for writing clean, maintainable Go programs in professional software development.

1

Create the greetings package

Create a file named greetings.go with a package called greetings. Inside it, write a function named WelcomeMessage that returns the string "Hello from the greetings package!".

Go

package greetings

// Write the WelcomeMessage function below
// Your code here

Hint

Remember to start with package greetings and define a function that returns the exact string.

2

Set up the main program

Create a file named main.go. Write the main package and import the fmt package and your custom greetings package.

Go

package main

import (
    "fmt"
    "greetings"
)

// Your code here

Hint

Use import with parentheses to include both fmt and greetings.

3

Call the WelcomeMessage function

Inside the main function, call greetings.WelcomeMessage() and store the result in a variable named message.

Go

package greetings

func WelcomeMessage() string {
    return "Hello from the greetings package!"
}

package main

import (
    "fmt"
    "greetings"
)

func main() {
    // Call greetings.WelcomeMessage() and save to message
    // Your code here
}

Hint

Use := to declare and assign the variable message.

4

Print the welcome message

Use fmt.Println to print the variable message inside the main function.

Go

package greetings

func WelcomeMessage() string {
    return "Hello from the greetings package!"
}

package main

import (
    "fmt"
    "greetings"
)

func main() {
    message := greetings.WelcomeMessage()
    // Print the message
    // Your code here
}

Hint

Use fmt.Println(message) to show the message on the screen.