Header File 

math.h  

Category 

Math Routines 

Prototype 

double floor(double x); 

long double floorl(long double x); 

Description 

Rounds down. 

floor finds the largest integer not greater than x.  

floorl is the long double version; it takes a long double argument and returns a long double result. 

Return Value 

floor returns the integer found as a double. floorl returns the integer found as a long double. 

Portability