Four preprocessor-specific operators are used in the context of the #define directive (see the following list for a summary of each). The stringizing, charizing, and token-pasting operators are discussed in the next three sections. For information on the defined operator, see The #if, #elif, #else, and #endif Directives.
| Operator | Action |
| Stringizing operator (#) | Causes the corresponding actual argument to be enclosed in double quotation marks |
| Charizing operator (#@) | Causes the corresponding argument to be enclosed in single quotation marks and to be treated as a character (Microsoft Specific) |
| Token-pasting operator (##) | Allows tokens used as actual arguments to be concatenated to form other tokens |
| defined operator | Simplifies the writing of compound expressions in certain macro directives |