We have already seen a few global data types, such as Numbers, Strings, and Booleans. Let's look at the Math, Date, and Random objects, which can be incredibly useful.

The Math objects provides us with the tools necessary to easily perform mathematical calculations.

`PI`

- 3.1415926...
`round(n)`

- Round
`n`to the nearest whole number. `sqrt(n)`

- Calculate squareroot of
`n`. `ceil(n)`

- Find the nearest whole number greater than a number
`n`. `floor(n)`

- Find the nearest whole number less than a number
`n`.

```
> Math.ceil(Math.PI)
4
> Math.sqrt(Math.PI)
1.7724538509055159
```

The Math.random() method calculates a random number between 0 and 1. Thus, to get a number between 1 and 10, we can multiple our decimal value by 10 and use the floor() method to get a whole integer value, then add 1.

```
> Math.random()
0.5574872007127851
> Math.floor((Math.random() * 10) + 1)
7
```

The `Date`

object allows us to find and manipulate the date. This includes finding the days of the week, time, current year, etc.

When working with Dates, you must instantiate a `Date`

object with the `new`

keyword. This new `Date`

object will hold the current date and time.

There are several ways you can instantiate a `Date`

object. Note that some values have a zero-based index (such as month), while others don't (like date).

```
> var date = new Date(2009, 9, 13, 3, 34, 44)
> date.toDateString()
"Tue Oct 13 2009"
> var date = new Date(2019, 9, 13)
> date.toDateString()
"Tue Oct 13 2019"
> var date = new Date('Mar 23, 1992 19:23:42')
> date.toDateString()
"Mon Mar 23 1992"
```

- Year
- 4 digit integer
- Month
- 0-11
- Day
- 1-31
- Hour
- 0-23
- Minutes
- 0-59
- Seconds
- 0-59
- Milliseconds
- 0-999

`get/setDate()`

- Return or set the day of the month.
`getDay()`

- Return day of the week (integer from 0 to 6).
`get/setFullYear()`

- Return or set the year (4-digit integer).
`get/setHours()`

- Get or set the hours (0 to 23).
`get/setMilliseconds()`

- Get or set milliseconds (0 to 999).
`get/setMinutes()`

- Get or set the number of minutes (0 to 59).
`get/setMonths()`

- Get or set the month (0 to 11).
`get/setTime()`

- Get or set the time. Number of milliseconds since Jan. 1 1970 (aka Unix time).
`getTimezoneOffset()`

- Returns timezone offset in minutes.
`toDateString()`

- Returns date as a string. eg.
`Wed Mar 15 2003`

`toTimeString()`

- Returns time as a string.
`toString()`

- Returns string of specified date.

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