Question

calculator: Write a program that takes three command-line arguments: number operator number and performs the required operation and prints the result on a single complete line in standard output.

(The four operators of a arithmetic, + * - /, must be recognized here.)

please use C++

Answer 1

#include <iostream>
#include <cstdlib>
using namespace std;

int main(int argc, char **argv) {
    if (argc == 4) {
        double n1 = atof(argv[1]);
        char ch = argv[2][0];
        double n2 = atof(argv[3]);

        if (ch == '+') {
            cout << n1 << "+" << n2 << " = " << n1+n2 << endl;
        } else if (ch == '-') {
            cout << n1 << "-" << n2 << " = " << n1-n2 << endl;
        } else if (ch == '*') {
            cout << n1 << "*" << n2 << " = " << n1*n2 << endl;
        } else if (ch == '/') {
            cout << n1 << "/" << n2 << " = " << n1/n2 << endl;
        } else {
            cout << "Invalid operation" << endl;
        }
    } else {
        cout << "Please provide operation in command line argument" << endl;
    }
    return 0;
}