| Syntax: | Default: |
| /Dname | Define no macros on the command line. |
| /Dname[=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.