关于计算用户输入百分比的简单 C++ 程序

Question

#include<iostream>
#include<conio.h>
using namespace std;
 int main()
{
    int amount; 
    int discount;
    cout<<"please enter amount : ";
    cin>>amount;

    discount = amount*(10/100);
    cout<<"the discount amount is"<<discount<<endl; 
    system("PAUSE");
}   

i am writing simple c++ program in which i wanted to get answer of input digits entered by user the simple mathematical equation is calculating in int amount variable but its not giving a required answer its giving a 0 but the code is correct i guess.

Answer 1

10/100 is integer division, which results in 0 . Hence you multiply the amount by zero, netting zero again.

Edit:

In case you come from a dynamic language like JavaScript or Python, they often use implicit double variables for everything, hence this would give you the expected value. C++ has a much stronger type system, so integral division will always yield another integer. If you wanted a division of floating point values you need to use floating point literals (or cast, but in this case it's not necessary):

discount = amount * 10.0 / 100.0;

Or, if float is enough precision for you:

discount = amount * 10.0f / 100.0f;