Classes and objects in C++ - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a class in C++?

A class is a blueprint or template for creating objects. It defines properties (data members) and behaviors (member functions) that the objects created from the class will have.

beginner

What is an object in C++?

An object is an instance of a class. It holds actual values for the properties defined by the class and can use the behaviors (functions) defined in the class.

beginner

How do you define a simple class with one integer property and a function to set it?

Example:
class MyClass {
public:
  int value;
  void setValue(int v) {
    value = v;
  }
};

intermediate

What is the difference between public and private members in a class?

Public members can be accessed from outside the class, while private members can only be accessed from within the class itself.

beginner

How do you create an object of a class and call its member function?

Example:
MyClass obj;  // create object
obj.setValue(10);  // call member function
int x = obj.value;  // access property

What keyword is used to define a class in C++?

A define

B object

C struct

D class

The keyword 'class' is used to define a class in C++.

Which of the following is true about objects?

A Objects are templates for classes

B Objects are instances of classes

C Objects cannot have functions

D Objects are the same as classes

Objects are instances created from classes.

What access specifier allows members to be accessed outside the class?

A private

B protected

C public

D internal

Public members can be accessed from outside the class.

How do you call a member function named 'setValue' on an object 'obj'?

A obj.setValue()

B setValue.obj()

C obj->setValue()

D obj:setValue()

Use dot notation: obj.setValue() to call a member function.

Which of these is NOT a member of a class?

A Objects

B Member functions

C Data members

D Constructors

Objects are instances of classes, not members inside a class.

Explain what a class and an object are in your own words.

Think about how a cookie cutter (class) makes cookies (objects).

Describe how access specifiers like public and private affect class members.

Imagine a house with a front door (public) and a locked safe inside (private).