How do I print different form of numbers?-CodePudding

TaskI am new to C and I have small problem. I want to make program where I scan two numbers and get their sum: e.g. Input: 1 2 Output: 3

Input. 1.1 2.2 Output: 3.3

I struggle with switching between float or int. If I scan for int(%d) I can't get float variable, but if I scanf float then as 1st output I get 3.00 instead of 3. By this I want to achieve that decimal number will be in decimal form and number like 3 in its form without decimal zeros.

Thanks

CodePudding user response：

You can read the two numbers with std::cin, then output the sum with std::cout.

You can use std::fixed and std::setprecision to control the format of the output. Demo

#include <iomanip>  // setprecision
#include <ios>  // fixed
#include <iostream>  // cin, cout

int main()
{
    double d1{0.0};
    double d2{0.0};
    std::cin >> d1 >> d2;
    std::cout << std::fixed << std::setprecision(5) << d1 << "   " << d2 << " = " << d1   d2 << "\n";
}

If you want to output decimals only when needed, just don't use fixed and precision. Demo

#include <iostream>  // cin, cout

int main()
{
    double d1{0.0};
    double d2{0.0};
    std::cin >> d1 >> d2;
    std::cout << d1 << "   " << d2 << " = " << d1   d2 << "\n";

    double d3{0.0};
    double d4{0.0};
    std::cin >> d3 >> d4;
    std::cout << d3 << "   " << d4 << " = " << d3   d4 << "\n";
}

CodePudding user response：

You can scan a std::string, check whether there is a dot in it using std::find and converting to an int (std::stoi) or a float (std::stof) accordingly. By the way, in C , you should use std::cin instead of scanf.