Write the function sum() with four parameters that calculates the arguments provided and returns their sum.
Use the default argument 0 to declare the last two parameter of the function sum().
Test the function sum() by calling it by all three possible methods.
Use random integers as arguments.
#include <iostream> #include <iomanip> #include <ctime> #include <cstdlib> using namespace std; long sum( long a1, long a2, long a3=0, long a4=0); int main() // Several calls to function sum() { cout << " **** Computing sums ****\n" << endl; /*w w w. j a va 2s. c o m*/ srand((unsigned int)time(NULL)); // Initializes the // random number generator. long res, a = rand()/10, b = rand()/10, c = rand()/10, d = rand()/10; res = sum(a,b); cout << a << " + " << b << " = " << res << endl; res = sum(a,b,c); cout << a << " + " << b << " + " << c << " = " << res << endl; res = sum(a,b,c,d); cout << a << " + " << b << " + " << c << " + " << d << " = " << res << endl; return 0; } long sum( long a1, long a2, long a3, long a4) { return (a1 + a2 + a3 + a4); }