change to map instead of vector

src/data.cpp

@@ -56,13 +56,14 @@ bool data::validate(const json &input) {
   const std::string phone = input.value("phone", "");
   const std::string email = input.value("email", "");
 
-  const std::vector<std::string> strings{name, address, phone, email};
+  const std::unordered_map<std::string, std::string> strings{
+      {"name", name}, {"address", address}, {"phone", phone}, {"email", email}};
 
   for (const auto &f : strings) {
-    if (f.size() == 0) {
+    if (f.second.size() == 0) {
       return false;
     }
-    if (f.size() >= 255) {
+    if (f.second.size() >= 255) {
       return false;
     }
   }