return a whole number in javascript code example

Example 1: round down the number javascript

+3.5 => +3.0
-3.5 => -4.0

+3.5 => +3.0 using Math.floor()
-3.5 => -3.0 using Math.ceil()

Example 2: how to know if a number has a decimal number js

function hasDecimal (num) {
	return !!(num % 1);
}
hasDecimal(2) // true
hasDecimal(2.345) // false