Structures
- structure refers to data that’s built up from other types (aka
struct) - structures bundle groups of related items together
- use structures to simplify parameter lists e.g.
routine(name, age, gender)vsroutine(employee) - use structures to reduce maintenance
🤔 What is the difference between a class and a structure? (in C++) A Structure is not secure and cannot hide its implementation details from the end-user while a class is secure and can hide its programming and designing details.
- use struct for plain-old-data structures without any class-like features;
- use class when you make use of features such as private or protected members, non-default constructors and operators, etc.
C has structs, it has no concept of encapsulation, so everything is public.
Pointers
- every pointer consists of two parts: a location in memory and a knowledge of how to interpret the contents of that location
Location in memory
- an address often expressed in hexadecimal notation
- the pointer only contains this address
Interpreting the contents
- if a pointer points to an integer, the compiler interprets the memory location given by the pointer as an integer
- memory doesn’t have any inherent interpretation associated with it
- a pointer error is usually the result of a pointer pointing somewhere it shouldn’t (memory corruption)
Global data
- global variables are accessible anywhere in the program
- used for preserving global values
- make variables local and global only if you need them
- you should have naming conventions to differentiate among local, class and global data
- anything you can do with global data, you can do better with access routines