add pointer

add "dynamic" heap array
add polymorphic

CPlusPlus/Pointer/main.cpp

@@ -0,0 +1,58 @@
+#include <iostream>
+
+using namespace std;
+
+void changeInteger(int n);
+void changeIntegerPerPointer(int* pN);
+int changeIntegerPerReturn(int n);
+void changeIntegerPerReference(int& n);
+
+int main()
+{
+	// general
+	int* pNumber = nullptr;
+	pNumber = new int(0);
+
+	cout << "size of pNumber: " << sizeof(pNumber) << endl;
+	cout << "size of pNumber data: " << sizeof(*pNumber) << endl;
+
+	*pNumber = 567;
+
+	//pNumber = new int(0); // BAD BAD - Memory Leak, because we override an existing pointer address with a new one without saving the old one
+	
+	// here are 100s of lines of code
+	
+	if (pNumber != nullptr)
+	{
+		delete pNumber;
+		pNumber = nullptr;
+	}
+
+	// pointer as references
+	int number = 0;
+	changeInteger(number);
+	changeIntegerPerPointer(&number);
+	changeIntegerPerPointer(pNumber);
+	changeIntegerPerReference(number);
+
+	return 0;
+}
+
+void changeInteger(int n)
+{
+	n = 100;
+}
+
+void changeIntegerPerPointer(int* pN)
+{
+	cout << "address of pN: " << &pN << endl;
+
+	if (pN == nullptr) return; // BE CAREFUL - if you don't what you get, do a test before
+
+	*pN = 200;
+}
+
+void changeIntegerPerReference(int& n)
+{
+	n = 300;
+}