c++ structs

c++_structs.md

structures & Review

structs

• a way to group different types of data
• Example:

struct product {
	float price;
	char name[41];
	char description[131];
	char distributor[131];
};

• considered data abstraction
• they can be used as a data type
• Class can do the same thing, but with overhead of extra features
• ; is required after creation of structs!
• cannot initialize within struct creation
  • no memory is allocated!
  • should initialize each field for safety at creation
• Typically created like global variables, before functions, outside of main
• compiler will not check if you've assigned everything to each field
  • will blow up if you attempted to call something that is undefined
• all memory is allocated during variable declaration for all fields in the struct

product item;
item.price = 15.99;
item.name = "iodine";
item.description = "yes good product";
item.distributor = "Freddies";

• we cannot read in an entire struct with cin
  • must read in each field individually and compose the struct
• setting two struct variables equal to one another will copy each field
  • item = item2
• structs can be passed by value, DO NOT DO
  • returnType function(product &struct)

review

• || truth table

or	T	F
T	T	T
F	T	F

• && truth table

&&	T	F
T	T	F
F	F	F

• before you can call a function it must be declared or defined