refactoring: removed redundant code from the function isValidPhoneNumber() and the constant from the function and added it to the header file.

src/createEmployeeAccount.c

@@ -69,21 +69,15 @@ bool isValidName(char* name,const int minimalLength)
 
 bool isValidPhoneNumber(char *phoneNumber)
 {
-    const int validNumberLength = 14;
     int numberLength = strlen(phoneNumber);
 
-    if(numberLength != validNumberLength)
-    {
-        return false;
-    }
-
-    if(phoneNumber[0]!='+' || phoneNumber[1]!='4' || phoneNumber[2]!='9')
+    /*this function checks if the 3 first characters a german suffix are*/
+    if(phoneNumber[0]!='+' || phoneNumber[1]!='4' || phoneNumber[2]!='9' || numberLength != validNumberLength)
     {
         return false;
     }
 
     return true;
-
 }
 
 int StringLengthCounter(char* string)

src/createEmployeeAccount.h

@@ -10,6 +10,7 @@
 #define minPasswordLength  5
 #define minimumNameLength  4
 #define maxLength  21
+#define validNumberLength  14
 
 struct employeesInformations
 {