added logic to ConData and Unittest for the function

src/main/c/ConvertMode.c

@@ -153,7 +153,17 @@ double getValue(int choice) {
             printf("\nThe convertet result is %dlf %d", result, Fluid[endingUnit]);
             break;
 
+        case 10://char Data[] = { 'B', 'KB', 'MB', 'GB', 'TB', 'PT' };
+            printf("\nEnter what the Unit is starting with (0 B, 1 KB, 2 MB , 3 GB, 4 TB, 5 PT): ");
+            scanf("%d", &startingUnit);
+
+            printf("\nEnter what the value should it be changed to (0 B, 1 KB, 2 MB , 3 GB, 4 TB, 5 PT): ");
+            scanf("%d", &endingUnit);
+
+            result = ConData(value, startingUnit, endingUnit);
 
+            printf("\nThe convertet result is %dlf %d", result, Data[endingUnit]);
+            break;
         }
     }
 }
@@ -201,9 +211,6 @@ double ConSpeed(double speed, int startingUnit, int endingUnit) {
 
 
 
-double ConData() {
-
-}
 
 double ConArea() {
 

src/main/c/main_taschenrechner.c

@@ -555,6 +555,201 @@ double ConLiterToGallon(double fluid, int startingUnit, int endingUnit) {
     }
 }
 
+double ConData(double data, int startingUnit, int endingUnit) {
+    switch (startingUnit)
+    {//'B', 'KB', 'MB', 'GB', 'TB', 'PT'
+    case 0: //B to x
+        switch (endingUnit)
+        {
+        case 0: //1
+            return data;
+            break;
+
+        case 1: //0.001
+            return data / 1000;
+            break;
+
+        case 2: //0.000001
+            return data / 1000000;
+            break;
+
+        case 3: //0.000000001
+            return data / 1000000000;
+            break;
+
+        case 4: //0.000000000001
+            return data / 1000000000000;
+            break;
+
+        case 5: //0.000000000000001
+            return data / 1000000000000000;
+            break;
+
+        default:
+            break;
+        }
+
+    case 1: //KB to x
+        switch (endingUnit)
+        {
+        case 0: //1000
+            return data * 1000;
+            break;
+
+        case 1: //1
+            return data;
+            break;
+
+        case 2: //0.001
+            return data / 1000;
+            break;
+
+        case 3: //0.000001
+            return data / 1000000;
+            break;
+
+        case 4: //0.000000001
+            return data / 1000000000;
+            break;
+
+        case 5: //0.000000000001
+            return data / 1000000000000;
+            break;
+
+        default:
+            break;
+        }
+
+    case 2: //MB to x
+        switch (endingUnit)
+        {
+        case 0: //0.000001
+            return data * 1000000;
+            break;
+
+        case 1: //0.001
+            return data * 1000;
+            break;
+
+        case 2: //1
+            return data;
+            break;
+
+        case 3: //0.001
+            return data / 1000;
+            break;
+
+        case 4: //0.000001
+            return data / 1000000;
+            break;
+
+        case 5: //0.000000001
+            return data / 1000000000;
+            break;
+
+        default:
+            break;
+        }
+
+
+    case 3: //GB to x
+        switch (endingUnit)
+        {
+        case 0: //0.000000001
+            return data * 1000000000;
+            break;
+
+        case 1: //0.000001
+            return data * 1000000;
+            break;
+
+        case 2: //1000
+            return data * 1000;;
+            break;
+
+        case 3: //1
+            return data;
+            break;
+
+        case 4: //0.001
+            return data / 1000;
+            break;
+
+        case 5: //0.000001
+            return data / 1000000;
+            break;
+
+        default:
+            break;
+        }
+
+
+    case 4: //TB to x
+        switch (endingUnit)
+        {
+        case 0: //0.000000000001
+            return data * 1000000000000;
+            break;
+
+        case 1: //0.000000001
+            return data * 1000000000;
+            break;
+
+        case 2: //1000000
+            return data * 1000000;;
+            break;
+
+        case 3: //1000
+            return data * 1000;
+            break;
+
+        case 4: //1
+            return;
+            break;
+
+        case 5: //0.001
+            return data / 1000;
+            break;
+
+        default:
+            break;
+        }
+
+
+    case 5: //PB to x
+        switch (endingUnit)
+        {
+        case 0: //0.000000000000001
+            return data * 1000000000000000;
+            break;
+
+        case 1: //0.000000000001
+            return data * 1000000000000;
+            break;
+
+        case 2: //1000000000
+            return data * 1000000000;;
+            break;
+
+        case 3: //1000000
+            return data * 1000000;
+            break;
+
+        case 4: //1000
+            return data * 1000;
+            break;
+
+        case 5: //1
+            return data;
+            break;
+
+        default:
+            break;
+        }
+    }
+}
+
+
 //..
 // graphMode
 void graphMode() {

src/main/c/taschenrechner.h

@@ -75,4 +75,6 @@ double ConLiter(double liter, int startingUnit, int endingUnit);
 
 double ConLiterToGallon(double fluid, int startingUnit, int endingUnit);
 
+double ConData(double data, int startingUnit, int endingUnit);
+
 #endif // TASCHENRECHNER_H

src/test/c/test_taschenrechner.c

@@ -83,5 +83,10 @@ void test_ConLiterToGallon(void) {//5 l to gallon
     TEST_ASSERT_EQUAL(1.32086, result);
 }
 
+void test_ConData(void) {//5 b to kb
+    double result = ConData(5, 0, 1);
+    TEST_ASSERT_EQUAL(0.005, result);
+}
+
 
 #endif // TEST