// Demonstrates structs and union types in C
// Compile: gcc union2.c
// Execute: a.out
//
#include <stdio.h>
int main(){


    // Declare a struct, comparable to a record
    // varData is a union which has 4 names for the same field
    struct transaction
    {
        int amount;
            
        union 
        {
            //int discount;
            double discount;
            long checkNumber;
            char cardNumber[6];
            char expireDate[6];
        } varData;
    };
    
     struct transaction myTrans;

    myTrans.amount = 3;
    printf("amount is %d\n\n", myTrans.amount);    // 3

    myTrans.varData.discount = 2.5;
    printf("discount should be 2.5 and it is %f\n", myTrans.varData.discount);    // ???

    myTrans.varData.checkNumber = 1234000;
    printf("checkNumber should be 1234000 and it is %d\n\n", 
                myTrans.varData.checkNumber);    // ???

    printf("discount should be 2.5 and it is %f\n", myTrans.varData.discount);    // ???
    
    printf("discount as an int is %d\n", myTrans.varData.discount);    // ???
    printf("checkNumber as a float is %f\n", myTrans.varData.checkNumber);    // ???
}