ES6
.EPSILON
Compares floating point numbers with a tolerance for rounding errors.
.isInteger(num)
console.log(Number.isInteger(1.05)) // false
console.log(Number.isInteger(1)) // true
console.log(Number.isInteger(-3.1)) // false
console.log(Number.isInteger(-3)) // true.isNaN
Checks whether num is the value NaN. In contrast to the global function isNaN(), it doesn’t coerce its argument to a number and is therefore safer for non-numbers:
console.log(isNaN('???')) // true
console.log(Number.isNaN('???')) // false.isFinite
Determines whether the passed value is a finite number
console.log(Number.isFinite(Infinity)) // false
console.log(Number.isFinite(123)) // true