add forward declaration examples

add classes

CPlusPlus/Intro/main.cpp

@@ -1,11 +1,26 @@
 #include <iostream>
 
+using namespace std;
+
 int main()
 {
+	// console output
 	std::cout << "Hello World" << std::endl;
 	std::cout << 1234 << std::endl;
 	std::cout << L"Noch ein Test!\n"; // wide string literal, cout can not handle this
 	std::cout << "Hello World" - 1234 << std::endl; // see pointer
 
+	int number = 10;
+
+	cout << "number: " << number << endl;
+
+	// console input
+	cin >> number;
+	cout << "input: " << number << endl;
+
+	char c;
+	cin >> c;
+	cout << "input: " << c << endl;
+
 	return 0;
 }