1. Open VS and click on Create a new project. Choose then an Empty Project (make sure it is a C++ project)and click Next.
   
2. Proceed by giving your project a name (e.g. "MyProject" and a location. Click Create.
3. Your project will then open. Here, you may edit the layout of VS as you want by dragging the different modules around.
   
4. To write our code, we will need a new file in our project. To add a new file, right-click on your project name → Add → New Item. You may also use the shortcut Ctrl + Shift + A.
   
5. Choose C++ File (.cpp), rename it if you want and click Add. The difference between a C++ File (.cpp) (often reffered to as only "cpp file" or "source file") and a Header File (.h) is very important and will be discussed later, but for now, just ignore it.
   
6. You have now made your first project! Continue reading at this page to learn how C++ is written.
   
   

To get a better understanding of how the code works, we will first implement the complete program and afterwards we will go through it step by step. To run the code, go to Debug → Start debugging/Start Without Debugging.

#include <iostream>
using namespace std;

int main() {
	cout << "Hello World!";
	return 0;
}

Alright, time to take a deeper look at the code. The first line is

#include <iostream>

In C++, much like in Python, we have to include libraries (headers) to perform certian actions, e.g. writing to file or solving math equations. iostream is the standard input/output streams library that enables us to print to screen (or e.g. a file).

using namespace std;

In this example we have chosen to include the line above to make getting into C++ easier. What using namespace std does is to silently insert std:: (std = standard) as a prefix to a lot of our standard functions. In the example above, cout will therefore be interpreted as std::cout. The short answer to why this is necessary is to specifiy where (which library) the function comes from in the case we have multiple functions with the same name. An analogy to this is how two students with the same name "Tom" are differentiated by adding e.g. the first letter of their last name; "Tom H." and "Tom B.".

By specifying the standard namespace for our entire program, we will avoid having to write std:: before many of our functions, which is benefitial when first learning C++. However, note that this shortcut comes with a cost. To learn more about these negatives, read this post on Stack Overflow explaining why it is considered a bad practice.

#include <iostream>

int main() {
	std::cout << "Hello World!";
	return 0;
}

Next up is

int main() {
	...
	return 0
}

What you see above is an example of a function in C++ (functions will be further covered later). The brackets " { " and " } " are in C++ used to group a block of statements, in this case those within the function main. Other examples where they are used are in e.g. for loops or if else statements. The equivilant to this in MATLAB is then end statement, and in Python it is the whitespace indent.

The special thing about the main function is that in C++, a program shall contain a global function named main, which is the designated start of the program (the only function called when running). This is very different from both Python and MATLAB, where programs can be written without using any functions at all.

To us, it means that every action we want to execute has to be described from within the main function, although you're of course allowed to call on other functions.

#include <iostream>
using namespace std;

cout << "Hello World!";

// Lines starting with "//" is a comment
// This code will result in an error when trying to build.

Lastly, we have

cout << "Hello World!";
// or, as previously mentioned
std::cout << "Hello World!";

cout is the standard output stream (stands for character output), and is what enables us to write to screen. cout is a statement, where "<<" is the insertion operator indicating what follows is inserted into cout. We will describe this even further in a later section. Also, notice that every statement is terminated with a semicolon ( ; ). Forgetting this is a very common source of error.

Congratulations, we have now not just made a simple program, but we have also dove deeper into the meaning of our code, thus already touching multiple important features in C++. For even more details on the Hello World example, visit this page.

As mentioned, variables can not be given any value without first beeing told what kind of data will be stored there. A full list of all variables and their size/precision can be found at the variable documentation, but some of the most used are

int myInteger					// e.g. -1, 2, 3 ...
unsigned int myPositiveInteger	// e.g. 0, 1, 2 ...
float myFloat					// e.g. -1.12, 2, 10e2 ...
double myDouble					// similar to float, but in general, float has 7 digits of precision while double has 15.
bool myBool						// 1, 0, true, false
char myChar						// 'a', 'b', 'v' ... One character
string myString					// "a", "Hello", "Hi again" ...			

In the example above, some variables are a bit different.

• String is not a fundamental type, and has to be included by it's own library, #include <string>
• Char is in itself only one character, but it may be combined into a type of string using arrays. We will not cover this here, but you may find more information about it on e.g. the char documentation.
  

When initializating variables in C++, three methods are used:

#include <iostream>
using namespace std;

int main() {
	int a(1);		// Method 1
	int b = 2;		// Method 2
	int c{ 3 };		// Method 3

	cout << a << endl << b << endl << c;	// "endl" means "end line" and makes a new line
	return 0;
}
// Output:
// 1
// 2
// 3

When working with different variables, keep in mind how the variable operates. An example of this is the int, which will always round down to the lowest integer.

#include <iostream>
using namespace std;

int main() {
	int a = 10;
	int b = 3;
	double c = 3;

	cout << a / b << endl;	// Output: 3, since a and b are ints -> result is an int
	cout << a / c << endl;	// Output: 3.33333, since c is a double -> result is a double
	cout << static_cast<float>(a) / static_cast<float>(b) << endl;	// Output: 3.33333, since we temporarily interpret the variables as floats
																	// To get a double, we may use only one static_cast<double> in the expression.
	return 0;
}

As shown, static_cast< new_type >( expression ) can temporarily convert a variable to another type in order to bypass the limits set by the original type. To read more about other type conversions, visit this page.

C++ has a lot of operators which when used correctly can make your code very efficient. Considering the scope of these operators, we will only cover the basics here, and leave you to visit further documentation to learn more about other operators, as well as their precedence.

Arithmetic operators

C++ supports five arithmetic operators, shown the the following table:

Note that compared to MATLAB or Python, we are in fact "missing" an operator , for exponentiation (power). In C++, this operator is instead included as the function pow( expression, exponent ).

int x = 3;
int y = 10;	

cout << x * x;		// 9
cout << pow(x, 2);	// 9
cout << 10y % 3x;		// 1

Relational and comparisonal operators

When comparing expressions, the following operators are used:

Logical operators

When evaluating logical operators, C++ only evaluates what is necessary to compute a result from left to right.

!true			// Evaluates to false
!(3 == 3)		// Evaluates to false
true || false	// Evaluates to true
true && false	// Evaluates to false

Increment and

decrement

Some much used operators in C++ are the increase ( ++ ) and decrease ( - - ) operators, which are equivalent to +=1 and -=1, respectively.

int x = 3;
x++;
cout << x;	// 4
x--;
cout << x;	// 3

The increase and decrease operations can be done in several ways, where each of the approaches below are equivalent to the others.

x++;
x += 1;
x = x + 1;


x--;
x -= 1;
x = x - 1;

Another interesting feature of these operators is that the ( ++ ) or ( - - ) can be used as either a prefix or a suffix (postfix), i.e. before or after the variable. Both uses will result in the same action, increasing or decreasing the variable by 1, but the difference lies in when the action is executed. By experience, many students find this confusing, so to ease into it, let's have a look at several examples. You may also read more about the difference here.

// We will only use ++ in the following examples, but the same rules apply to --
// Ex. 1
int x = 4;
int y = x++;

cout << y << endl;	// 4
cout << x << endl;	// 5
// Here, ++ is used as a suffix, hence y is set equal to the value of x before x is increased by 1


// Ex. 2
int x = 4;
int y = ++x;

cout << y << endl;	// 5
cout << x << endl;	// 5
// Here, ++ is used as a prefix, hence x is increased by 1 (now equal to 5) before y is set equal to the value of x


// Ex. 3
int x = 4;

cout << ++x << endl;	// 5
// Here, ++ is used a prefix, hence x is increase by 1 (now equal to 5) before it is printed to the screen


// Ex. 4
int x = 4;

cout << x++ << endl;	// 4
// Here, ++ is used as a suffix, hence the value of x (currently 4) is printed to the screen before it it increased by 1.
// However, if we were to print or use x on the next line, it would have the value 5
cout << x << endl; 		// 5