Static members vs instance members in C Sharp (C#) - Quick Revision & Key Differences

Recall & Review

beginner

What is a static member in C#?

A static member belongs to the class itself, not to any specific object. It can be accessed without creating an instance of the class.

beginner

What is an instance member in C#?

An instance member belongs to a specific object created from a class. You need to create an object to access instance members.

intermediate

Can static members access instance members directly? Why or why not?

No, static members cannot access instance members directly because instance members belong to objects, and static members belong to the class itself without any object context.

beginner

How do you call a static method and an instance method in C#?

You call a static method using the class name (e.g., ClassName.Method()), and you call an instance method using an object of the class (e.g., objectName.Method()).

beginner

Example: What will this code print?
<pre>class Car {
  public static int wheels = 4;
  public string color;
  public Car(string c) { color = c; }
}

Console.WriteLine(Car.wheels);
Car myCar = new Car("red");
Console.WriteLine(myCar.color);</pre>

It will print:
4
red
Because 'wheels' is static and accessed by class name, and 'color' is instance and accessed by object.

Which of these belongs to the class itself, not to any object?

A Parameter

B Static member

C Local variable

D Instance member

Static members belong to the class itself and can be accessed without creating an object.

How do you access an instance member in C#?

A Using the class name

B Directly without any reference

C Using an object of the class

D Using the static keyword

Instance members require an object to be accessed because they belong to that specific object.

Can a static method access instance variables directly?

A Yes, always

B Only inside constructors

C Only if the instance variables are public

D No, because instance variables belong to objects

Static methods do not have access to instance variables because they do not belong to any object.

What keyword is used to declare a static member in C#?

A static

B instance

C const

D readonly

The 'static' keyword declares a member that belongs to the class itself.

If you want a property shared by all objects of a class, which should you use?

A Static member

B Instance member

C Local variable

D Parameter

Static members are shared across all instances of the class.

Explain the difference between static members and instance members in your own words.

Think about whether you need to create an object to use the member.

Describe a real-life example where you would use a static member versus an instance member.

Imagine a car factory: number of wheels is same for all cars, color is different per car.