fruitOrder.c

/*
 * Program with enum, struct and union
 */

#include <stdio.h>

typedef enum {
	COUNT, POUNDS, PINTS
} unit_of_measure;

typedef union {
	short count;
	float weight;
	float volume;
} quantity;

typedef struct {
	const char *name;
	const char *country;
	// union type: quantity
	quantity amount;
	// enum type: unit_of_measure
	unit_of_measure units;
} fruit_order;

void display(fruit_order order) {
	printf("This order contains ");
	if (order.units == PINTS) {
		printf("%2.2f pints of %s\n", order.amount.volume, order.name);
	} else if (order.units == POUNDS) {
		printf("%2.2f lbs of %s\n", order.amount.weight, order.name);
	} else {
		printf("%i %s\n", order.amount.count, order.name);
	}
}

int main() { 
	fruit_order apples = {"apples", "England", .amount.count = 144, COUNT};

	fruit_order strawberries = {"strawberries", "Spain", .amount.weight = 17.6, POUNDS};

	fruit_order oj = {"orange juice", "U.S.A", .amount.volume = 10.5, PINTS};

	display(apples);
	display(strawberries);
	display(oj);
	return 0;
}