diff --git a/TinySTL/Test/StringTest.cpp b/TinySTL/Test/StringTest.cpp
index 1fa0572..9498ae4 100644
--- a/TinySTL/Test/StringTest.cpp
+++ b/TinySTL/Test/StringTest.cpp
@@ -394,6 +394,21 @@ namespace TinySTL{
 			auto found = str.find_last_not_of("023456789", str.size() - 2);
 			assert(found == 0);
 		}
+		void testCase25(){
+			tsStr str = "We think in generalities, but we live in details.";
+
+			auto s = str.substr(3, 5);
+			assert(TinySTL::Test::container_equal(s, tsStr("think")));
+		}
+		void testCase26(){
+			tsStr str1("green apple");
+			tsStr str2("red apple");
+
+			assert(str1.compare(str2) != 0);
+			assert(str1.compare(6, 5, "apple") == 0);
+			assert(str2.compare(str2.size() - 5, 5, "apple") == 0);
+			assert(str1.compare(6, 5, str2, 4, 5) == 0);
+		}
 	}
 }
 
@@ -418,11 +433,13 @@ int main(){
 	//testCase17();
 	//testCase18();
 	//testCase19();
-	testCase20();
-	testCase21();
-	testCase22();
-	testCase23();
-	testCase24();
+	//testCase20();
+	//testCase21();
+	//testCase22();
+	//testCase23();
+	//testCase24();
+	//testCase25();
+	//testCase26();
 	system("pause");
 	return 0;
 }
\ No newline at end of file
diff --git a/TinySTL/Test/StringTest.h b/TinySTL/Test/StringTest.h
index 4c332ec..8353cd7 100644
--- a/TinySTL/Test/StringTest.h
+++ b/TinySTL/Test/StringTest.h
@@ -38,6 +38,8 @@ namespace TinySTL{
 		void testCase22();
 		void testCase23();
 		void testCase24();
+		void testCase25();
+		void testCase26();
 	}
 }