{{keywords>wiki library source code example reference}}
===== floor =====
<code cpp>
    double floor(double);
</code>
rounding down a number

===== cpp Sourcecode Example =====
<code cpp>     
#include <iostream> /* including standard library */
#include <cmath> /* including math library */

using namespace std;
int main ( void ) 
{
    double y,x;
    x = 4.2;
    y = 9.9;

    //cout.setf(ios::fixed, ios::floatfield);
    cout.precision(8);

    cout << "floor of " << x << " is " << floor(x) << endl;
    cout << "floor of " << y << " is " << floor(y) << endl;
    return 0;
}

</code>

==== output ====
   output:
   floor of 4.2 is 4
   floor of 9.9 is 9