diff --git a/test.cpp b/test.cpp
index 09f53c8..5fe251f 100644
--- a/test.cpp
+++ b/test.cpp
@@ -2,6 +2,7 @@
 #include <sstream>
 #include <type_traits>
 #include <stdexcept>
+#include <tuple>
 #include "String.h"
 #include <gtest/gtest.h>
 
@@ -54,38 +55,68 @@ TEST(StringTest, uninitializedStringcStrThrows)
     EXPECT_THROW(str.c_str(), std::runtime_error);
 }
 
-TEST(StringTest, addable)
-{
-    String str1("cica");
-    String str2("sajt");
+using str3 = std::tuple<const char*, const char*, const char*>;
+class addStringTest : public ::testing::TestWithParam<str3>
+{};
 
-    EXPECT_STREQ("cicasajt", (str1+str2).c_str());
+TEST_P(addStringTest, addable)
+{
+    String str1(std::get<0>(GetParam()));
+    String str2(std::get<1>(GetParam()));
+
+    EXPECT_STREQ(std::get<2>(GetParam()), (str1+str2).c_str());
 }
 
-TEST(StringTest, plusequalsAddable)
+TEST_P(addStringTest, plusEqualsable)
 {
-    String str1("cica");
-    String str2("sajt");
+    String str1(std::get<0>(GetParam()));
+    String str2(std::get<1>(GetParam()));
     str1 += str2;
 
-    EXPECT_STREQ("cicasajt", str1.c_str());
+    EXPECT_STREQ(std::get<2>(GetParam()), str1.c_str());
 }
 
-TEST(StringTest, addableChar)
+static const std::vector<str3> testvalues1 =
+        {
+                std::make_tuple("cica", "sajt", "cicasajt"),
+                std::make_tuple("sajtos", " cica", "sajtos cica"),
+                std::make_tuple("szeretem", " a sajtot", "szeretem a sajtot"),
+                std::make_tuple("meg ", "a cicákat", "meg a cicákat"),
+                std::make_tuple("ennyi már ", "elég lesz", "ennyi már elég lesz")
+        };
+
+INSTANTIATE_TEST_CASE_P(testGroup1, addStringTest, ::testing::ValuesIn(testvalues1));
+
+using strcharstr = std::tuple<const char*, char, const char*>;
+class addCharStringTest : public ::testing::TestWithParam<strcharstr>
+{};
+
+TEST_P(addCharStringTest, addCharable)
 {
-    String str("cicá");
+    String str(std::get<0>(GetParam()));
 
-    EXPECT_STREQ("cicák", (str+'k').c_str());
+    EXPECT_STREQ(std::get<2>(GetParam()), (str+std::get<1>(GetParam())).c_str());
 }
 
-TEST(StringTest, plusequalsAddableChar)
+TEST_P(addCharStringTest, plusEqualsCharable)
 {
-    String str("sajto");
-    str+='k';
+    String str(std::get<0>(GetParam()));
+    str+=std::get<1>(GetParam());
 
-    EXPECT_STREQ("sajtok", str.c_str());
+    EXPECT_STREQ(std::get<2>(GetParam()), str.c_str());
 }
 
+static const std::vector<strcharstr> testvalues2 =
+        {
+                std::make_tuple("cicá", 'k', "cicák"),
+                std::make_tuple("sajto", 'k', "sajtok"),
+                std::make_tuple("C++1", '1', "C++11"),
+                std::make_tuple("sö", 'r', "sör"),
+                std::make_tuple("te", 'j', "tej")
+        };
+
+INSTANTIATE_TEST_CASE_P(testGroup1, addCharStringTest, ::testing::ValuesIn(testvalues2));
+
 TEST(StringTest, comparable)
 {
     String str1("cica");