# Metadata
Platforms: desktop, server, mobile OS: mac, windows, linux, ios, android Introduced: 1.0 Security:
# Syntax
the commandNames
# Examples
the commandNames
if field "Name" is among the lines of the commandNames then exit repeat
# Description
Use the commandNames function to check whether a particular command already exists in LiveCode, to avoid using a reserved word for your own custom handlers.
The commandNames function returns all the commands that can be used in LiveCode, including synonyms.
# Tags
# See
- **keyword:** line - **function:** propertyNames, functionNames - **glossary:** handler, LiveCode, command, return, reserved word - **control structure:** on, function