Every thing in a computer is represented as bits (1s and 0s)

double is like float but for bigger numbers.

Integer division

Happens automatically based on types!

Explicit casting

int a = 20;
int b = 8;
a / b

// output: 2

static_cast<double>(a) / b

// output: 2.500000

Include #pragma once so that you don't redefine stuff

Macros

#define SEVEN 7

then use it like this:

std::cout << "message: " << SEVEN + num << std::endl;

void is a function that does not return anything

File I/O

#include <fstring>


ifstream infile(argv[1]);
if (!infile.is_open())
{
	cerr << "unable to open file for reading:" << argv[1] << endl;
	return 2;
}

ofstream outfile(argv[2]);
if (!outflie.is_open())
{

}

Use -Wall to turn on all warnings using g++

For example g++ -std==c++17 -Wall -o sums sum.cpp