Base keyword behavior in C Sharp (C#) - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the base keyword do in C#?

The <code>base</code> keyword lets a derived class access members (methods, properties, constructors) of its base class. It helps call or refer to the base class version of a member.

beginner

How do you use <code>base</code> to call a base class constructor?

You use <code>base(arguments)</code> in the derived class constructor's initializer to call a specific base class constructor before running the derived constructor's body.

intermediate

Can base be used to access overridden methods?

Yes. Inside an overridden method, <code>base.MethodName()</code> calls the base class version of that method, bypassing the override.

beginner

What happens if you don't use base when overriding a method?

If you don't use <code>base</code>, the derived class method completely replaces the base class method. The base method is not called unless explicitly invoked with <code>base</code>.

intermediate

Can <code>base</code> be used to access base class fields directly?

No. <code>base</code> cannot be used to access base class fields directly if they are private. It works with accessible members like protected or public fields, properties, and methods.

What is the purpose of the base keyword in C#?

A To access members of the base class from a derived class

B To create a new instance of a class

C To declare a new class

D To override a method

The base keyword is used to access members of the base class from within a derived class.

How do you call a base class constructor with parameters from a derived class?

A Using <code>this(parameters)</code> in the derived constructor

B Using <code>base(parameters)</code> in the derived constructor initializer

C By calling <code>new BaseClass(parameters)</code> inside the derived constructor

D You cannot call base class constructors explicitly

You call a base class constructor by using base(parameters) in the derived class constructor's initializer.

Inside an overridden method, how do you call the base class version of that method?

A Using <code>super.MethodName()</code>

B Using <code>this.MethodName()</code>

C You cannot call the base method once overridden

D Using <code>base.MethodName()</code>

You use base.MethodName() to call the base class version of an overridden method.

Can base be used to access private fields of the base class?

A Only if the derived class is in the same namespace

B Yes, always

C No, private fields are not accessible even with <code>base</code>

D Only if the field is static

Private fields are not accessible from derived classes, even with base.

What happens if you override a method but do not call base.Method() inside it?

A The base method is not executed

B The base method is automatically called

C The program will not compile

D The base method is called twice

If you don't call base.Method(), the base method is not executed when the override runs.

Explain how the base keyword helps when overriding methods in C#.

Think about how to run the original method from the base class when you have a new version in the derived class.

Describe how to use base to call a base class constructor from a derived class constructor.

Remember the syntax after the colon in the derived constructor.