C# Global Tutorial – Easy Global Example with Full Code
Imagine you just moved into a new house 🏡. You start unpacking, but every time you need something—like a toothbrush 🪥 or your phone charger 🔌—you have to search through different boxes in different rooms. Annoying, right? 😖
Now, imagine if you had one special box labeled “Important Stuff” 📦, which always contains your most-used items. No more searching—just grab and go! That’s exactly what the global statement in C# does! It allows you to define commonly used namespaces globally, so you don’t have to include them in every file.
Let’s dive in and see how it works! 🚀
What You Are Going to Learn in This Lesson?
✔️ What is the global statement in C#?
✔️ Why is it useful?
✔️ A real-world example to make it fun!
✔️ A Global Example C# with complete code and output.
✔️ How it simplifies your code.
What is the Global Statement in C#?
The global statement in C# allows you to declare namespaces once and use them across your entire project. Before this feature, you had to include using statements in every file. But now, with global using directives, you can reduce redundancy and keep your code clean!
Before Global Statements (Old Way) 🤯
If you had multiple files, you’d have to repeat the same using statements everywhere:
File 1: Person.cs
using System; // Required in every file
class Person
{
public void SayHello()
{
Console.WriteLine("Hello from Person class!");
}
}
File 2: Program.cs
using System; // Required again!
class Program
{
static void Main()
{
Person person = new Person();
person.SayHello();
}
}
After Global Statements (New Way) 🎉
Now, you can define common namespaces globally in one place and remove them from individual files!
File 1: GlobalUsings.cs (Create This File Once)
global using System; // This is now available everywhere!
File 2: Person.cs (No Need to Include ‘using System’)
class Person
{
public void SayHello()
{
Console.WriteLine("Hello from Person class!");
}
}
File 3: Program.cs (No Need to Include ‘using System’)
class Program
{
static void Main()
{
Person person = new Person();
person.SayHello();
}
}
Real-World Example: A Global Toolbox for a Car Workshop 🚗
Imagine you run a car repair shop 🛠️. You have different mechanics working on different tasks.
- One mechanic fixes engines.
- Another checks tires.
- Someone else handles paint jobs.
But all of them need basic tools like wrenches, screwdrivers, and hammers 🔧🔨. Instead of making each mechanic carry their own toolbox, you create a shared toolbox 🧰 that everyone can access.
This is exactly what global using directives do—they create a shared toolbox of namespaces that every file in your project can use!
Complete Global Example C#
Let’s create a car repair system using the global statement to keep the code clean.
Step 1: Create a GlobalUsings.cs File (Shared Toolbox)
global using System;
global using System.Collections.Generic;
Step 2: Create a Car.cs File (A Car Object)
class Car
{
public string Model { get; set; }
public Car(string model)
{
Model = model;
}
}
Step 3: Create a Mechanic.cs File (Mechanic Working on the Car)
class Mechanic
{
public void Repair(Car car)
{
Console.WriteLine($"Mechanic is repairing the {car.Model}");
}
}
Step 4: Create a Program.cs File (Main Program Execution)
class Program
{
static void Main()
{
Car myCar = new Car("Tesla Model S");
Mechanic mechanic = new Mechanic();
mechanic.Repair(myCar);
}
}
Expected Output:
Mechanic is repairing the Tesla Model S
How This Works?
✔️ We declared System and System.Collections.Generic globally in GlobalUsings.cs.
✔️ We did not include using System; in any other files.
✔️ The code still works perfectly because the global statement made those namespaces available everywhere.
✔️ Our files are now cleaner and easier to read! 🎉
When Should You Use Global Statements?
🟢 Good Use Cases:
✅ In large projects where you use the same namespaces repeatedly.
✅ When working with .NET APIs that require frequent imports.
✅ To keep code clean and organized.
🔴 Avoid When:
❌ You’re working on small projects (it won’t make much difference).
❌ You need specific namespaces only in certain files.
Conclusion
So, what did we learn today? Global statements let us declare namespaces once and use them everywhere. It’s like having a shared toolbox for all your files! This makes code cleaner, removes repetition, and improves readability. 🚀
Next What?
In the next lesson, you’ll learn about the ‘Required’ expression in C#. Ever wanted to make sure an object always has certain properties set? That’s exactly what we’ll explore next! Stay tuned and keep coding! 💡🔥
If you have difficulty or questions, drop a comment. We will be happy to help you. 😊
