#ece244

struct Student {
	string name;
	int ID;
	double height;
}

struct Student x;
x.name = "Cindy";
void print(string n) {
	// code to print stuff
}

classes

A class is an expansion to structs that bundles together data and functions. It is a user-defined data type.

• A class is essentially a blueprint or a template
• Creating an instance of the class (creating a variable out of it) is an object.
• Each object is independent, meaning changes to one object don't affect other objects.

e.g. string class in C++

The definition of a Class goes inside a header file.

// student.h
class Student {
	int ID;
	string name;
	void print();
};

abstraction

• private: access controller on members of a class that can only be used inside a class
  • accessible anywhere inside of a function member of a class
• public: access controller on members allowing members to be accessed anywhere, both inside and outside the class.

// student.h
// header file that just defines the Student class
class Student {
	private:
		int ID;
		string name;
	public:
		Student(); // constructor
		void print();
		void setName(string n);
		string getName();
};

//students.cpp
#include <iostream>
#include "student.h"
using namespace std;

void Student::print() {
	// adding logic to the print() function
	// which was defined in the Student class
	cout << "Student name " << name;
	cout << "Student ID " << ID;
}

string Student::getName() {
	// adding logic to the getName() function
	// which was defined in the Student class
	return name;
}

void Student::setName(string n) {
	name = n;
}

Student::Student() { // constructor
	ID = 0;
	name = "no name";
}

//main.cpp
#include "Student.h"
int main(void) {
	// create an object of Student
	Student x; // so essentially Student is a data type here
	Student y;
	// another Student obj, independent of the other obj but using the same template
	x.ID = 4078; // this doesn't work because ID is a private data member
	// can't be accessed outside of the Student class
	x.setName("abigail");
	x.getName(); // returns "abigail"
	
	y.print(); // this is an issue because name and ID are uninitialized
	// so we can use a Constructor
}

constructor

A constructor is a function that always gets called when a new object of a class is created. To see more: L07 Constructors, Destructors, Dynamic Memory Allocation