Refactor currencyExchange

src/currencyExchange.c

@@ -1,19 +1,17 @@
 #include "currencyExchange.h"
 
-float convert(float euro, int newCurrencyCode) {
-    switch(newCurrencyCode) {
-        case CURRENCY_CODE_USD:
-            return ( euro * USD_RATE_OF_ONE_EURO );
-
-        case CURRENCY_CODE_GBP:
-            return ( euro * GBP_RATE_OF_ONE_EURO );
+#define NUM_CURRENCIES 4
 
-        case CURRENCY_CODE_JAPANESE_YEN:
-            return ( euro * JAPANESE_YEN_RATE_OF_ONE_EURO );
-
-        case CURRENCY_CODE_CHINESE_YUAN:
-            return ( euro * CHINESE_YUAN_RATE_OF_ONE_EURO );
+float exchangeRates[NUM_CURRENCIES] = {
+    USD_RATE_OF_ONE_EURO,
+    GBP_RATE_OF_ONE_EURO,
+    JAPANESE_YEN_RATE_OF_ONE_EURO,
+    CHINESE_YUAN_RATE_OF_ONE_EURO
+};
 
+float convert(float euro, int newCurrencyCode) {
+    if (newCurrencyCode >= 0 && newCurrencyCode < NUM_CURRENCIES) {
+        return euro * exchangeRates[newCurrencyCode];
     }
     
     return -1;