# Classes: Constants

A class can contain constants, which are similar to variables, except that their value cannot be changed.

```
class Constants
{
public const float PI = 3.14;
}
```

## Constant Access

Refer to Expressions: Class Operations - Constant Access for more information.

## Constant Visibility

Constants can be declared as `public`

, `protected`

or `private`

.

```
class Constants
{
public const float PI = 3.14;
protected const float E = 2.71;
private const float GOLDEN_RATIO = 1.618;
}
```

## Final Constants

Constants can be declared as `final`

, which means that they cannot be overridden in a child class.

```
class Constants
{
final public const float PI = 3.14;
}
```