### /D Compiler Option

Syntax: | Default:
/D name | Define no macros on the command line.
/D name[=n] |

Use /D to define preprocessor macro name to the value n. If /Dname is specified, n defaults to 1. If either /Dname= or /Dname:: is specified, the macro is set to a null string. Macros defined on the command line override macros defined in the source code.

If the value n is more than one word, delimit it with double quotes:

    /Dname="a b c"

To define n to a string literal, delimit the string literal with \" at either end, and enclose the whole in double quotes:

    /Dname="\"Some text\" "

To use the backslash (\) in a string, precede it with another backslash. For example:

    /Dname="\"C:\\IBMCPP\""

will be read as

    #define name "C:\IBMCPP"

Use the /U option to undefine macros on the command line. By default, no macros are defined on the command line.

Summary of Compiler Options