# null

#### Availability

Flash Player 5.

#### Usage

    null

#### Parameters

None.

#### Returns

Nothing.

#### Description

Keyword; a special value that can be assigned to variables, or returned by a function if no data was provided. You can use `null` to represent values that are missing or do not have a defined data type.

#### Example

In a numeric context, `null` evaluates to 0. Equality tests can be performed with `null`. In this statement, a binary tree node has no left child, so the field for its left child could be set to `null`.

    if (tree.left == null) {
    	tree.left = new TreeNode();
    }