# 12.4. The `Math`

Object¶

JavaScript provides several built-in objects, which can be called directly by
the user. One of these is the `Math`

object, which contains more than the
standard mathematical operations (`+, -, *, /`

).

In the previous sections, we learned how to construct, modify, and use objects
such as `giraffe`

. However, JavaScript built-in objects cannot be modified
by the user.

Unlike other objects, the

`Math`

object isimmutable.

## 12.4.1. `Math`

Properties Are Constants¶

The `Math`

object has 8 defined properties. These represent *mathematical
constants*, like the value for pi (π) or the square root of 2.

Instead of defining a variable to hold as many digits of pi as we can remember,
JavaScript stores the value for us. To use this value, we do NOT need to
create a new object. By using dot notation and calling `Math.PI`

, we can
access the value of pi.

Example

1 2 3 | ```
console.log(Math.PI);
console.log(Math.PI*4);
console.log(Math.PI + Math.PI);
``` |

**Console Output**

```
3.141592653589793
12.566370614359172
6.283185307179586
```

As stated above, the properties within `Math`

*cannot* be changed by the
user.

Example

1 2 3 4 5 | ```
console.log(Math.PI);
Math.PI = 1234;
console.log(Math.PI);
``` |

**Console Output**

```
3.141592653589793
3.141592653589793
```

To use one of the other constants stored in `Math`

, we replace `PI`

with
the property name (e.g. `SQRT2`

stores the value for the square root of 2).

## 12.4.2. Other `Math`

Properties¶

Besides the value of pi, JavaScript provides 7 other constants. How useful you find each of these depends on the type of project you need to complete.

More powerful uses of the `Math`

object involve using *methods*, which we
will examine next.