{{keywords>wiki library source code example reference}} ===== floor ===== double floor(double); rounding down a number ===== C Sourcecode Example ===== compile in linux with: gcc floor.c -o floor **-lm** -Wall #include /* including standard library */ //#include /* uncomment this for Windows */ #include /* including math library */ int main ( void ) { double y,x; x = 4.2; y = 9.9; printf("floor of %f is %f\n", x, floor(x) ); printf("floor of %f is %f\n ",y , floor(y) ); return 0; } ==== output ==== output: user@host:~$ ./floor floor of 4.200000 is 4.000000 floor of 9.900000 is 9.000000