Firebase Docs Reference Interface: Number rules.Number interface static A value of type Integer or type Float See rules.Integer and rules.Float. Except as otherwise noted, the content of this page is licensed under the Creative Commons Attribution 3.0 License, and code samples are licensed under the Apache 2.0 License. For details, see our Site Policies. Java is a registered trademark of Oracle and/or its affiliates. Last updated May 2, 2018.