Lecture 3 --- Classes
- Classes in C++; Types and defining new types; Example: A Date class;
- Class declaration: member variables and member functions; Using the class member functions;
- Member function implementation; Class scope; Classes vs. structs; Designing classes;
- Defining a custom sort of class instances.
3.1 Types and Defining New Types
- Every C++ object has a type (e.g., integers, doubles, strings, and vectors, etc., including custom types); and a class is a custom data type, also known as a user-defined data type. – The type tells us what the data means and what operations can be performed on the data.
3.2 C++ Classes
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A C++ class group together variables and functions that operate on those variables. We call these variables member variables, and we call these functions member functions.
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A C++ class consists of
– a collection of member variables, usually private, and – a collection of member functions, usually public, which operate on these variables.
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public member functions can be accessed directly from outside the class,
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private member functions and member variables can only be accessed indirectly from outside the class, through public member functions.