A, jQuery in decimal rounding, the rounding method
1. discarding the fractional part, the integer part reserved
parseInt(5/2) =2
2. rounding.
Math.round(5/2) =3
3. rounded down
Math.floor(5/2) =2
Math object's methods
parseInt(5/2) =2
Math.round(5/2) =3
Math.floor(5/2) =2
Math object's methods