A pure function is a function that will always return the same result every time it is given the same input. The result doesn't depend on any information or state and won't produce a side effect, or a change of the system state outside of the function. Let's take a look at the following piece of code:
/* pure_function_1.cpp */
#include <iostream>
using namespace std;
float circleArea(float r)
{
return 3.14 * r * r;
}
auto main() -> int
{
cout << "[pure_function_1.cpp]" << endl;
// Initializing a float variable
float f = 2.5f;
// Invoking the circleArea() function
// passing the f variable five times
for(int i = 1; i <= 5; ++i)
{
cout << "Invocation " << i << " -> ";
cout << "Result of circleArea(" << f << ") = ";
cout << circleArea(f) << endl;
}
return...