4. C++ OOP

How is a method implemented in C++

Usually outside of the class, using the scope resolution operator ::

Car::Car() {}

What is the scope resolution operator ::

Links a method implementation to its class

What goes in the header file (.h)

Contains class definitions

What goes in the source file (.cpp)

Contains method implementations and code

What are the three types of scope that C++ structures can be defined as

private

public

protected — private but accessible to subclasses

how do you define a class in C+ in the header file

class Car{
private:
	int milesDriven;
	int age;

public:
	Car();
	void drive(int miles);
};

how do you initialise an object in C++

Car::Car() {
	milesDriven = 0;
	age = 10;

How do you define a class in the source file in C++

void Car::drive(int miles) {
	milesDrive += miles;
}

What is a stack-allocated object

Declared like normal variables, and automatically destroyed when scope ends.

What is a heap-allocated objecet

Created with new, returned as a pointer, and must be deleted manually.

How does a pointer work in C++

Declared with *, accessed with →

How does references to objects work in C++

Declared with & , must be initialised, immutable and accessed with.

What pass-by method does C++ use

Pass by value (copies of variables)

what is <iostream> in c++

input/output streams (replaces stdio.h)

What is <string> in C++

The string class (wrapper around char arrays)

How do strings work in C++

• C-style string (char *)

• high-level (std::string)

what methods does string have

• length

• find

• substr

• append

  • replace

how does ‘cin’ work in C++

reads input

int age;
std::cin >> age;

how does ‘cout’ work in C++

std::cout << "hello, " << name << "!";

what is a namespace

they group related identifiers (classes, functions, variables) to avoid name collisions. the standard library lives in the std namespace.

How do you access a namespace member

:: notation

how do you define a namespace

namespace MyMath {
	int add(int a, int b){
		return a + b;
	}
}

how do you use a method defined inside a namespace

int x = MyMath::add(3, 5);