Why interfaces are used in Go - See It in Action

Why interfaces are used

📖 Scenario: Imagine you are building a program that handles different types of notifications, like emails and SMS messages. Each notification type sends messages differently, but your program should treat them the same way when sending.

🎯 Goal: Learn how to use interfaces in Go to write flexible code that can work with different notification types without changing the main sending logic.

📋 What You'll Learn

Create a struct for Email notification

Create a struct for SMS notification

Define an interface called Notifier with a method Send

Implement the Send method for both Email and SMS structs

Write a function that accepts the Notifier interface and calls Send

Demonstrate sending notifications using the interface

💡 Why This Matters

🌍 Real World

Interfaces are used in real programs to handle different data types with common behavior, like payment methods, shapes in graphics, or notification systems.

💼 Career

Understanding interfaces is key for Go developers to write clean, reusable, and scalable code in professional software projects.

1

DATA SETUP: Create Email and SMS structs

Create two structs called Email and SMS. The Email struct should have a field Address of type string. The SMS struct should have a field PhoneNumber of type string.

Go

# Your code here

Hint

Use type Email struct { Address string } and similarly for SMS.

2

CONFIGURATION: Define Notifier interface

Define an interface called Notifier with a method Send() that returns nothing.

Go

package main

type Email struct {
    Address string
}

type SMS struct {
    PhoneNumber string
}

// Your code here

Hint

Use type Notifier interface { Send() } to define the interface.

3

CORE LOGIC: Implement Send method for Email and SMS

Implement the Send() method for both Email and SMS structs. For Email, print "Sending email to " followed by the Address. For SMS, print "Sending SMS to " followed by the PhoneNumber.

Go

package main

type Email struct {
    Address string
}

type SMS struct {
    PhoneNumber string
}

type Notifier interface {
    Send()
}

// Your code here

Hint

Define methods with func (e Email) Send() and func (s SMS) Send() that print the messages.

4

OUTPUT: Use Notifier interface to send notifications

Create a function called Notify that takes a parameter n of type Notifier and calls n.Send(). Then create an Email with Address "[e-mail]" and an SMS with PhoneNumber "[phone]". Call Notify with both values. Print the output.

Go

package main

type Email struct {
    Address string
}

type SMS struct {
    PhoneNumber string
}

type Notifier interface {
    Send()
}

func (e Email) Send() {
    println("Sending email to " + e.Address)
}

func (s SMS) Send() {
    println("Sending SMS to " + s.PhoneNumber)
}

// Your code here

Hint

Define Notify function and call it with Email and SMS instances inside main().