Map use cases in Go - Mini Project: Build & Apply

Map use cases

📖 Scenario: You are managing a small library system. You want to keep track of books and their availability status using a map in Go.

🎯 Goal: Build a Go program that uses a map to store book titles as keys and their availability (true for available, false for checked out) as values. Then, filter and display only the available books.

📋 What You'll Learn

Create a map called library with exact book titles as keys and boolean values for availability

Create a variable called availableBooks to store available books

Use a for loop with variables title and available to iterate over library

Add available book titles to availableBooks

Print the availableBooks slice

💡 Why This Matters

🌍 Real World

Maps are useful to store and quickly access data by keys, like book titles in a library system.

💼 Career

Understanding maps and slices is essential for backend development, data processing, and building efficient Go applications.

1

Create the library map

Create a map called library with these exact entries: "The Hobbit": true, "1984": false, "Pride and Prejudice": true, "The Catcher in the Rye": false

Go

// Create the map called library with the given book titles and availability
// Your code here

Hint

Use map[string]bool to create the map with book titles as keys and availability as boolean values.

2

Create the availableBooks slice

Create a variable called availableBooks as an empty slice of strings to store titles of available books

Go

package main

import "fmt"

func main() {
    library := map[string]bool{
        "The Hobbit": true,
        "1984": false,
        "Pride and Prejudice": true,
        "The Catcher in the Rye": false,
    }
    // Create an empty slice called availableBooks
    // Your code here
}

Hint

Use []string{} to create an empty slice of strings.

3

Filter available books

Use a for loop with variables title and available to iterate over library. Inside the loop, if available is true, append title to availableBooks

Go

package main

import "fmt"

func main() {
    library := map[string]bool{
        "The Hobbit": true,
        "1984": false,
        "Pride and Prejudice": true,
        "The Catcher in the Rye": false,
    }
    availableBooks := []string{}
    // Loop over library and add available books to availableBooks
    // Your code here
}

Hint

Use for title, available := range library to loop over the map. Use append to add to the slice.

4

Print available books

Write fmt.Println(availableBooks) to display the list of available books

Go

package main

import "fmt"

func main() {
    library := map[string]bool{
        "The Hobbit": true,
        "1984": false,
        "Pride and Prejudice": true,
        "The Catcher in the Rye": false,
    }
    availableBooks := []string{}
    for title, available := range library {
        if available {
            availableBooks = append(availableBooks, title)
        }
    }
    // Print the availableBooks slice
    // Your code here
}

Hint

Use fmt.Println(availableBooks) to print the slice.