floor static method
Returns the largest (closest to positive infinity) double value that is less than or equal to the argument a
and is equal to a mathematical integer.
Implementation
static num floor(num a) {
if (a is int) return a;
if (a is double) {
if (a.isNaN || a.isInfinite) return a;
}
var n = a.toInt();
return n;
}