CO2402: Advanced Programming
with C++ Lecture 6
Constructors in C++
1. Introduction to Constructors
o Constructors are special member functions in a class that are
automatically called when an object is instantiated. They
initialize the object's data members.
Example: The StackClass constructor initializes the stack top to 0.
2. Syntax and Characteristics
o A constructor has the same name as the class and no return type,
not even void.
o It can be defined with or without parameters. The version without
parameters is called the default constructor.
Example:
, 3. Function Overloading with Constructors
o Constructors can be overloaded to allow different ways of initializing
an object. Each constructor must have a unique parameter list.
Example:
4. Initialisation Section
o The initialization section can be used to initialize class members
before entering the constructor body. It appears after the
constructor's parameter list and starts with a colon.
Example:
5. Best Practices
o Always provide a constructor to ensure proper initialization of
objects.
o If no constructor is defined, C++ provides a default constructor.
However, relying on the compiler-generated constructor can be
risky, as it may not initialize data members properly.
with C++ Lecture 6
Constructors in C++
1. Introduction to Constructors
o Constructors are special member functions in a class that are
automatically called when an object is instantiated. They
initialize the object's data members.
Example: The StackClass constructor initializes the stack top to 0.
2. Syntax and Characteristics
o A constructor has the same name as the class and no return type,
not even void.
o It can be defined with or without parameters. The version without
parameters is called the default constructor.
Example:
, 3. Function Overloading with Constructors
o Constructors can be overloaded to allow different ways of initializing
an object. Each constructor must have a unique parameter list.
Example:
4. Initialisation Section
o The initialization section can be used to initialize class members
before entering the constructor body. It appears after the
constructor's parameter list and starts with a colon.
Example:
5. Best Practices
o Always provide a constructor to ensure proper initialization of
objects.
o If no constructor is defined, C++ provides a default constructor.
However, relying on the compiler-generated constructor can be
risky, as it may not initialize data members properly.
