modf(var x, var* p): var
Splits x in a fractional and integer part, each of which has the same sign as x.
x - any number.
p - var
pointer, or 0 if the integer part is not needed.
Fractional part of x. Integer part is stored in *p.
var x = modf(123.456,&y); // x = 0.456 and y = 123.0