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#if

To define more generalized conditions. Multiple conditions are connected by relational operators such as AND(&&), OR(||). #define USA 1 // #define EUP 1 #include <stdio.h> #if ((1>0) && defined USA)        #define currency_rate 46 #endif #if (defined (EUP))    #define currency_rate 100 #endif main() {     int rs;     rs = 10 * currency_rate;     printf ("%d\n", rs); } 460