Empty interface in Go - Mini Project: Build & Apply

Using Empty Interface in Go

📖 Scenario: You are building a simple program that can store different types of values in a single list. This is useful when you want to handle mixed data like numbers, text, and boolean values together.

🎯 Goal: Create a Go program that uses an empty interface to hold different types of values in a slice, then print each value.

📋 What You'll Learn

Create a slice called items that can hold any type of value using the empty interface.

Add exactly these values to items: 42, "hello", true.

Use a for loop with the variable item to go through items.

Print each item inside the loop.

💡 Why This Matters

🌍 Real World

Empty interfaces let Go programs handle data when the type is not known in advance, like reading JSON or working with mixed data.

💼 Career

Understanding empty interfaces is important for Go developers working with flexible data structures, APIs, or libraries that accept any type.

1

Create a slice of empty interface

Create a slice called items of type []interface{} and add these exact values: 42, "hello", true.

Go

# Create the slice items with 42, "hello", and true
# Your code here

Hint

Use []interface{} to create a slice that can hold any type.

2

Add a counter variable

Add a variable called count of type int and set it to 0 before the loop.

Go

package main

func main() {
    items := []interface{}{42, "hello", true}
    // Create count variable here
    # Your code here
}

Hint

Just write count := 0 before the loop.

3

Loop through the slice

Use a for loop with the variable item to go through items. Inside the loop, increase count by 1.

Go

package main

func main() {
    items := []interface{}{42, "hello", true}
    count := 0
    // Loop through items and increase count
    # Your code here
}

Hint

Use for _, item := range items to loop and count++ to add one each time.

4

Print each item

Inside the for loop, use fmt.Println(item) to print each item. Also, import the fmt package at the top.

Go

package main

// Import fmt package
import "fmt"

func main() {
    items := []interface{}{42, "hello", true}
    count := 0
    for _, item := range items {
        count++
        // Print item here
        # Your code here
    }
}

Hint

Use fmt.Println(item) inside the loop to print each value.