# Number (function)

#### Availability

Flash Player 4.

#### Usage

    Number(expression)

#### Parameters

`expression` An expression to convert to a number.

#### Returns

Nothing.

#### Description

Function; converts the parameter `expression` to a number and returns a value as follows:

If `expression` is a number, the return value is `expression`.

If `expression` is a Boolean value, the return value is 1 if `expression` is `true`, 0 if `expression` is `false`.

If `expression` is a string, the function attempts to parse `expression` as a decimal number with an optional trailing exponent, that is, 1.57505e-3.

If `expressionx` is `undefined`, the return value is 0.

This function is used to convert Flash 4 files containing deprecated operators that are imported into the Flash 5 authoring environment. See the `&` operator for more information.

#### See also

Number object