Arithmetic operators

In C++ there are the usual arithmetic operators as in most other programming languages, namely addition, subtraction, multiplication, division and the remainder operator (modulo). In addition, there are the one-digit operators for positive and negative sign.

Code Example

#include <iostream>
#include <iomanip>	// Library for specifying the decimal places
using namespace std;

int main() {
	int a = 4, b = 6;
	long c = 7;
	double z = 0;
	cout << "Starting values" << endl;
	cout << "a = " << a << "\nb = " << b << "\nc = " << c << endl;

	cout << "Calculations" << endl;
	z = (double)a / (double)b;
	// setprecision() = Funktion from library <iomanip>,
	// for specifying the decimal places
	cout << "z = a / b = " << setprecision(2) << z << endl;

	if (a % 2 == 0) {
		cout << "Number " << a << " = even" << endl;
	} else {
		cout << "Number " << a << " = odd" << endl;
	}
}

Output

Starting values
a = 4
b = 6
c = 7
Calculations
z = a / b = 0.67
Number 4 = even

Code Explanation

1. The code includes two libraries, iostream and iomanip. iostream provides input and output functionality, while iomanip allows specifying the decimal places.
2. Inside the main() function, several variables are declared and initialized:
   • a is an int variable initialized with the value 4.
   • b is an int variable initialized with the value 6.
   • c is a long variable initialized with the value 7.
   • z is a double variable initialized with the value 0.
3. The cout statements are used to display information on the console. They use the << operator to insert values and strings into the output stream.
4. The line cout << "Starting values" << endl; outputs the string “Starting values” followed by a newline character.
5. The subsequent cout statement displays the values of variables a, b, and c using the << operator. Each value is inserted into the output stream.
6. The line cout << "Calculations" << endl; outputs the string “Calculations” followed by a newline character.
7. The line z = (double)a / (double)b; performs a calculation and assigns the result to the variable z. The (double) type casting is used to ensure that the division is performed with floating-point arithmetic.
8. The line cout << "z = a / b = " << setprecision(2) << z << endl; displays the value of z with a precision of 2 decimal places using the setprecision() function from the iomanip library. The setprecision() function modifies the behavior of the << operator.
9. The if statement is used to perform a conditional check. It checks if the value of a is even or odd.
10. If the condition a % 2 == 0 is true (meaning a is divisible by 2 with no remainder), the code block inside the if statement is executed. It outputs the string “Number a = even” where a is the value of the variable.
11. If the condition a % 2 == 0 is false (meaning a is not divisible by 2 with no remainder), the code block inside the else statement is executed. It outputs the string “Number a = odd” where a is the value of the variable.