Lecture 3: Constructors and Destructors

Constructors

• A constructor is a special member function that is executed automatically whenever an object is created.
• It allows an object to initialize itself when it's first created, without requiring a separate call to a member function.
• Constructors are used for automatic initialization of objects.

Default Constructor

• A default constructor is a constructor with no parameters.
• In the Counter class, the default constructor Counter() : count(0) initializes the count to 0.

Counter Example

• The Counter class is an example of a class that might be useful as a general-purpose programming element.
• A counter is a variable that counts things, such as file accesses, user presses, or customer entries.
• The Counter class has one data member: count of type unsigned int.
• The class has three member functions:
  • The constructor Counter() to initialize the count.
  • inc_count() to increment the count.
  • get_count() to return the current value of the count.

Member Functions

• inc_count() is a member function that adds 1 to the count.
• get_count() is a member function that returns the current value of the count.

Classes and Structures

• Classes and structures are similar, but with some differences (to be discussed later).

Overloaded Constructors

• Overloaded constructors are not discussed in this lecture, but will be covered later.

Member Functions Defined Outside the Class

• Member functions can be defined outside the class definition, but will be covered later.

Learn about constructors and destructors in programming, including default constructors, overloaded constructors, and member functions defined outside the class.