C++ examples for Function:Function Return
Use a constant expression to represent the value of PI, calculate the area of a circle based on a radius value entered by the user.
#include <iostream> // get an approximate value of PI constexpr double getPi() { return (double) 22 / 7; } int main() { /* w w w . j av a 2 s.c o m*/ float radius; std::cout << "Enter the radius of the circle: "; std::cin >> radius; // the area equals PI * the radius squared double area = getPi() * (radius * radius); std::cout << "\nCircle's area: " << area << std::endl; return 0; }