# D

Defines a symbol name that can be associated with an optional value.

## Syntax

Linux: | -D name[=value]

macOS: | -D name[=value]

Windows: | /D name[=value]

## Arguments

name | Is the name of the symbol.
value | Is an optional integer or an optional character string delimited by double quotes; for example, D name=string.

## Default

noD | Only default symbols or macros are defined.

## Description

Defines a symbol name that can be associated with an optional value. This definition is used during preprocessing in both Intel® Fortran conditional compilation directives and the fpp preprocessor. The Dname=value will be ignored if there are any non-alphabetic, non-numeric characters in name.

If a value is not specified, name is defined as "1".

If you want to specify more than one definition, you must use separate D options.

If you specify noD, all preprocessor definitions apply only to fpp and not to Intel® Fortran conditional compilation directives. To use this option, you must also specify the fpp option.

### CAUTION

Linux and macOS

If you are not specifying a value, do not use D for name, because it will conflict with the -DD option.

## IDE Equivalent

Visual Studio: General > Preprocessor Definitions

Preprocessor> Preprocessor Definitions

Preprocessor > Preprocessor Definitions to FPP only

## Alternate Options

D | Linux and macOS: None Windows: /define:name[=value]
noD | Linux and macOS: -nodefine Windows: /nodefine

Parent topic: Preprocessor Options

## See Also

Using Predefined Preprocessor Symbols