OOP access to private area

OOP/src/accessToAddress_privateArea.cpp

@@ -0,0 +1,44 @@
+//
+//  main.cpp
+//  practice
+//
+//  Created by 김천규 on 12/02/2019.
+//  Copyright © 2019 김천규. All rights reserved.
+//
+
+#include <iostream>
+#include <string>
+
+using namespace std;
+
+class Test {
+    private :
+    int hidden;
+    public :
+    int opened;
+    Test(int val);
+};
+
+Test::Test(int val) {
+    hidden = val;
+//    cout << &hidden << endl;
+}
+
+int main(int argc, const char * argv[]) {
+
+    Test *test = new Test(100);
+
+    cout << "-------- 값 --------" << endl;
+    test->opened = 20;
+    // cout << test->hidden << endl; //'hidden' is a private member of 'Test'
+    cout << "test member variable hidden value"<< *(&test->opened -1) << endl;
+    cout << "test member variable opened value" << test->opened << endl;
+
+    cout << "-------- 주소 --------" << endl;
+    cout << "test instance address : "<< &test << endl;
+    cout << "test member variable hidden address : " << (&test->opened -1)<< endl;
+    cout << "test member variable opened address : " << &test->opened << endl;
+
+    delete test;
+    return 0;
+}