These two types are on a string return that same string, with the cases converted to either lower or upper cases. It is very helpful functions for converting text to uppercase and lowercase.Syntax: var lower = text.toLowerCase(); and var upper = text.toUpperCase()
The Math.floor() function returns the largest integer less than or equal to a given number. On the other hand, the floor() function rounds a number down and returns an integer value.
isNaN() can be used to check if a certain value or expression evaluates to NaN. It means Not-A-Number.isNan() does not convert value to a number. This method returns true if the value is of the type Number, and equates to Nan. Otherwise, it returns false.