Help picking out decimals from whole numbers?

Gregory Sakas (72)
In C++, is there anyway to see if a number divided by another is a whole number or not, and have that number disregarded if it a decimal. For example, if I have a program that divides two user-inputted numbers, and the user puts in 2 and 3, have the program output: "The number is a decimal". But if they put 4 and 2, have the program output: "The quotient is 2".
Danishx83 (77)
In C++, is there anyway to


If you can think it, then there is a way for it in C++

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#include <iostream>

int main(){

int x,y;  //for user input
int z;  //for storing remainder

std::cin >> x >> y;  //take inputs

z=x%y;  //calculate remainder

if(z>0)  //if remainder greater than zero
std::cout << "The number is a decimal";  //print message
else  //otherwise
std::cout << "The quotient is " << x/y;  //print message and answer

return 0;

}

Last edited on
newbieg (764)
So I've got a question here, why do some people call the function cin by calling the std library?

Example;
you wrote std::cin>>x>>y; and std::cout<<"The quotient...";

I would write cin>>x>>y; and cout<<"The quotient ...";

My compiler doesn't mind either way that it's written, so why bother calling std::? Is it just proper computer grammar at this point?
Last edited on
andywestken (4094)
std is a namespace
http://www.cplusplus.com/doc/tutorial%20/namespaces/

If you are using just cout << "Hi!" << endl; rather than std::cout << "Hi!" << std::endl; then you must have a line somwhere above that says using namespace std;

The using directive tells the compiler to look in that namespace as well as the global namespace when looking for a symbol. That is, if you are "using namespace std", when it fails to find "cout" in the global namespace, it automatically tries "std::cout".

It is seen as better practice to avoid using directives at global scope as it avoids "cross-talk" between different namespaces. But it is not uncommon to use "using namespace std" for smaller bits of code.

I generally code with explicit std::s unless I'm doing a lot of (e.g.) string manipulation. But then I use the using directive within function scope, so only the relevant functions see the whole of standard namespace.

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#include <iostream>

void my_function(){
  using namespace std;

  int x=0, y=0;  //for user input

  cin >> x >> y;  //take inputs

  int z=x%y;  //calculate remainder

  if(z>0)  //if remainder greater than zero
    cout << "The number is a decimal";  //print message
  else  //otherwise
    cout << "The quotient is " << x/y;  //print message and answer
}

int main(){
  std::cout << "testing..." << std::endl;
  my_function();
  return 0;
}
Last edited on
Danishx83 (77)
Its not grammar,
it called namespace
you must be using the code
using namespace std;
or
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using std::cin;
using std::cout;

the you can just write
cin >> x >> y;
Other wise you have to use
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std::cin >>x >> y;
std::cout << "Something";


Read this for more
http://www.cplusplus.com/doc/tutorial/namespaces/
newbieg (764)
OK, makes sense. I just always include using namespace std; in all my coding to this point so I didn't even notice that your code above didn't have it.
Huh, kind of cool, I didn't know you could write it like that, Thanks.
Gregory Sakas (72)
Thanks for the help! Problem = solved!
Danishx83 (77)
@andywestken
using directive within function scope, so only the relevant functions see the whole of standard namespace.


Thanks for a good idea
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