# U

Undefines any definition currently in effect for the specified symbol.

## Syntax

Linux: | -U name

macOS: | -U name

Windows: | /U name

## Arguments

name | Is the name of the symbol to be undefined.

## Default

OFF | Symbol definitions are in effect until they are undefined.

## Description

This option undefines any definition currently in effect for the specified symbol.

On Windows systems, use the /u option to undefine all previously defined preprocessor values.

## IDE Equivalent

Visual Studio: Preprocessor > Undefine Preprocessor Definitions

## Alternate Options

Linux and macOS: None

Windows: /undefine:name

Parent topic: Preprocessor Options

## See Also

u (Windows) compiler option