C# Programming Examples Of Variables And Data Types

Hey there! Today, we’re going to play around with variables and data types in C#. Think of variables as little storage boxes where you keep different kinds of data—numbers, text, or even true/false values. And data types? Well, they tell C# what kind of data can go into those boxes.

We’ll keep things super simple with easy-to-follow examples. You’ll see how to declare variables, store values, and even convert between different types.

No boring theory

Just code, Quick explanations, and Fun!

Value Type Example

1. Declare and Print a Variable

Question:

Write a C# program to declare a variable name of type string and assign your name to it. Print the value.

Hint:

Use string to store text.
Use Console.WriteLine() to print.

Solution:

				
					using System;

class Program
{
    static void Main()
    {
        string name = "Steven";
        Console.WriteLine("My name is " + name);
    }
}

Output

				
					My name is Steven

Explanation:

Declared a string variable name and stored "Steven".
Used Console.WriteLine() to print it.

2. Add Two Integers

Question:

Write a program to declare two integers and print their sum.

Hint:

Use int for whole numbers.
Use + for addition.

Solution:

				
					using System;

class Program
{
    static void Main()
    {
        int num1 = 10;
        int num2 = 20;
        int sum = num1 + num2;

        Console.WriteLine("Sum: " + sum);
    }
}

Output

				
					Sum: 30

Explanation:

Declared two int variables and assigned values.
Added them and stored in sum.
Printed the result.

3. Boolean Variable Example

Question:

Declare a bool variable and print its value.

Hint:

Use true or false.

Solution:

				
					using System;

class Program
{
    static void Main()
    {
        bool isStudent = true;
        Console.WriteLine("Am I a student? " + isStudent);
    }
}

Output

				
					Am I a student? True

Explanation:

Declared bool and assigned true.

4. Convert int to double

Question:

Declare an int, convert it to double, and print both.

Hint:

Use (double) to convert an int to double.

Solution:

				
					using System;

class Program
{
    static void Main()
    {
        int number = 5;
        double converted = (double)number;

        Console.WriteLine("Integer: " + number);
        Console.WriteLine("Double: " + converted);
    }
}

Output

				
					Integer: 5
Double: 5

Explanation:

Declared an int variable.
Used (double) to convert it.
Printed both values.

5. Convert string to int

Question:

Take a number as a string, convert it to an integer, and print.

Hint:

Use int.Parse() to convert.

Solution:

				
					using System;

class Program
{
    static void Main()
    {
        string strNumber = "100";
        int number = int.Parse(strNumber);

        Console.WriteLine("Converted Number: " + number);
    }
}

Output

				
					Converted Number: 100

Explanation:

Stored "100" as string.
Used int.Parse() to convert it.
Printed the converted value.

6. Explicit Type Conversion (double to int)

Question:

Convert a double to an int and print both.

Hint:

Use (int) for explicit conversion.

Solution:

				
					using System;

class Program
{
    static void Main()
    {
        double num = 9.8;
        int intNum = (int)num;

        Console.WriteLine("Double: " + num);
        Console.WriteLine("Integer: " + intNum);
    }
}

Output

				
					Double: 9.8
Integer: 9

(Note: The fractional part .8 is truncated during explicit type casting from double to int.)

Explanation:

Stored "100" as string.
Used int.Parse() to convert it.
Printed the converted value.

Reference Data Type Example

7. String Example (Reference Behavior)

Question:

Write a program to declare two string variables. Assign one to another and modify one of them. Observe what happens when you print both.

Hint:

Strings are immutable (they don’t change in memory).
Modifying one won’t affect the other.

Solution:

				
					using System;

class Program
{
    static void Main()
    {
        string firstName = "John";
        string secondName = firstName; // Copy reference

        secondName = "David"; // Modify secondName

        Console.WriteLine("First Name: " + firstName);
        Console.WriteLine("Second Name: " + secondName);
    }
}

Explanation:

Assigned "John" to firstName.
Assigned firstName to secondName.
Changed secondName to "David", but firstName remains "John".
This proves that string variables don’t share memory locations (immutable behavior).

Output

				
					First Name: John
Second Name: David

Explanation:

Even though we assigned firstName to secondName, strings are immutable.
Changing secondName to "David" does not affect firstName.

8. Class Example (Reference Sharing Behavior)

Question:

Create a Person class with a name field. Assign one object to another and modify one. Observe how both change.

Hint:

Classes are reference types.
Changing one object affects the other.

Solution:

				
					using System;

class Person
{
    public string name;
}

class Program
{
    static void Main()
    {
        Person person1 = new Person();
        person1.name = "Alice";

        Person person2 = person1; // Both refer to the same memory

        person2.name = "Bob"; // Modify person2

        Console.WriteLine("Person1 Name: " + person1.name);
        Console.WriteLine("Person2 Name: " + person2.name);
    }
}

Explanation:

Created a Person class with a name field.
person1 is assigned to person2 (both now refer to the same object).
Changing person2.name also affects person1.name.
This proves objects share the same memory when assigned.

Output

				
					Person1 Name: Bob
Person2 Name: Bob

Explanation:

person1 and person2 refer to the same object in memory.
Changing person2.name = "Bob" also changes person1.name because both point to the same instance.

9.Array Example (Reference Type Behavior)

Question:

Create an integer array. Assign one array to another and modify one of the elements. Observe how both arrays are affected.

Hint:

Arrays are reference types.
Changing one affects the other.

Solution:

				
					using System;

class Program
{
    static void Main()
    {
        int[] numbers1 = { 1, 2, 3 };
        int[] numbers2 = numbers1; // Both refer to the same memory

        numbers2[0] = 99; // Modify numbers2

        Console.WriteLine("numbers1[0]: " + numbers1[0]);
        Console.WriteLine("numbers2[0]: " + numbers2[0]);
    }
}

Explanation:

Declared an integer array numbers1.
Assigned numbers1 to numbers2, making them share the same reference.
Modified numbers2[0] = 99, which also affected numbers1[0].
This proves arrays work as reference types.

Output

				
					numbers1[0]: 99
numbers2[0]: 99

Explanation:

Arrays are reference types, so both numbers1 and numbers2 point to the same array in memory.
Changing numbers2[0] = 99 also affects numbers1[0].

10. Object Example (Reference Behavior in Action)

Question:

Create a Car class with a model field. Create an object, assign it to another, and modify one. Observe how both objects change.

Hint:

Objects are reference types.
Modifying one affects the other.

Solution:

				
					using System;

class Car
{
    public string model;
}

class Program
{
    static void Main()
    {
        Car car1 = new Car();
        car1.model = "Tesla";

        Car car2 = car1; // Both refer to the same memory

        car2.model = "Ford"; // Modify car2

        Console.WriteLine("Car1 Model: " + car1.model);
        Console.WriteLine("Car2 Model: " + car2.model);
    }
}

Explanation:

Created a Car class with a model field.
Assigned car1 to car2, making them share the same memory reference.
Modified car2.model, which also changed car1.model.
This confirms objects are reference types.

Output

				
					Car1 Model: Ford
Car2 Model: Ford

Explanation:

car1 and car2 share the same memory reference.
Modifying car2.model = "Ford" also changes car1.model.

Conclusion

Great job! 🎉 You just explored value types and reference types in C# with real examples. Now, you understand how variables, data types, and type conversion work—and how reference types behave differently from value types.

Here’s a quick recap:

✅ Value types (int, double, bool) store data directly.
✅ Reference types (string, class, array, object) store a memory reference instead of actual data.
✅ Strings are immutable, so modifying one doesn’t affect its copy.
✅ Classes, arrays, and objects share references, so changing one affects all.

The best way to master this? Experiment! Try modifying values, changing references, and observing the results. Keep coding, keep learning, and soon, you’ll be writing powerful C# programs like a pro! 💻

Complete C# Tutorial

C# Programming Examples Of Variables And Data Types

No boring theory

Value Type Example

1. Declare and Print a Variable

2. Add Two Integers

3. Boolean Variable Example

4. Convert int to double

5. Convert string to int

6. Explicit Type Conversion (double to int)

Reference Data Type Example

7. String Example (Reference Behavior)

Explanation:

8. Class Example (Reference Sharing Behavior)

Explanation:

9.Array Example (Reference Type Behavior)

Explanation:

10. Object Example (Reference Behavior in Action)

Explanation:

Explanation:

Conclusion

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