Why generics are needed in C Sharp (C#) - See It in Action

Why generics are needed

📖 Scenario: Imagine you run a small shop and want to keep track of different types of items you sell, like books and toys. You want a way to store these items safely without mixing them up or losing their specific details.

🎯 Goal: You will build a simple program that shows why generics are useful in C#. You will first create separate lists for books and toys, then see how generics help you avoid repeating code and keep your data safe.

📋 What You'll Learn

Create two separate lists: one for string book titles and one for string toy names.

Create a generic list that can hold any type of item.

Add items to the generic list and show how it works for both books and toys.

Print the contents of each list to see the difference.

💡 Why This Matters

🌍 Real World

Generics are used in many programs to create reusable and safe code that works with different data types, like lists of customers, products, or messages.

💼 Career

Understanding generics is important for software developers to write clean, efficient, and error-free code that can handle many data types without duplication.

1

Create separate lists for books and toys

Create a List<string> called bookTitles with these exact values: "C# Basics" and "Learn LINQ". Also create a List<string> called toyNames with these exact values: "Teddy Bear" and "Lego Set".

C Sharp (C#)

# Create the bookTitles and toyNames lists with the given values
# Your code here

Need a hint?

Use List<string> and initialize with the exact values inside curly braces.

2

Create a generic list for any item type

Create a generic List<T> called items that can hold any type. For now, create a List<string> called items and leave it empty.

C Sharp (C#)

using System;
using System.Collections.Generic;

class Program
{
    static void Main()
    {
        List bookTitles = new List { "C# Basics", "Learn LINQ" };
        List toyNames = new List { "Teddy Bear", "Lego Set" };

        // Create a generic list called items
        // Your code here
    }
}

Need a hint?

Use List<string> to create the items list.

3

Add books and toys to the generic list

Add the first book title from bookTitles to items. Then add the first toy name from toyNames to items. Use items.Add() for both.

C Sharp (C#)

using System;
using System.Collections.Generic;

class Program
{
    static void Main()
    {
        List bookTitles = new List { "C# Basics", "Learn LINQ" };
        List toyNames = new List { "Teddy Bear", "Lego Set" };

        List items = new List();

        // Add the first book title and first toy name to items
        // Your code here
    }
}

Need a hint?

Use items.Add(bookTitles[0]) and items.Add(toyNames[0]) to add items.

4

Print all lists to see the difference

Print the contents of bookTitles, toyNames, and items using Console.WriteLine inside a foreach loop. Print each list's name before its items.

C Sharp (C#)

using System;
using System.Collections.Generic;

class Program
{
    static void Main()
    {
        List bookTitles = new List { "C# Basics", "Learn LINQ" };
        List toyNames = new List { "Teddy Bear", "Lego Set" };

        List items = new List();

        items.Add(bookTitles[0]);
        items.Add(toyNames[0]);

        // Print all lists with their names
        // Your code here
    }
}

Need a hint?

Use foreach loops to print each list's items with Console.WriteLine.