added tutorial 16 cpp file from local machine

Author: SevenLinesOfCode

tut16.cpp

@@ -0,0 +1,50 @@
+#include <iostream>
+using namespace std;
+
+int sum(int a, int b) {
+    int c = a + b;
+    return c;
+};
+
+// This will not swap a and b.
+void swap(int a, int b) {
+    int temp = a;
+    a = b;
+    b = temp;
+};
+
+// Call by reference using pointers
+// This will swap a and b. this will swap the value at address of a and b
+void swapPointer(int* a, int* b) {
+    int temp = *a;
+    *a = *b;
+    *b = temp;
+};
+
+// Call by reference using C++ refrence variable
+// This will swap a and b. this will swap the value at address of a and b
+void swapReferenceVar(int &a, int &b) {
+    int temp = a;
+    a = b;
+    b = temp;
+};
+
+int main () {
+    
+    int x = 4, y = 3;
+    // cout<<"The sum of 4 and 3 is: "<<sum(x, y)<<endl;
+
+    //swapping variables
+    cout<<"Initially the value of x and y was: "<<x<<" and "<<y<<" respectively."<<endl;
+
+    // swap(x, y); // This will not swap a and b.
+
+    // swapPointer(&x, &y); // This will swap a and b using pointers.
+
+    swapReferenceVar(x, y); // This will swap a and b using reference variable.
+
+    cout<<"Finally the value of x and y is: "<<x<<" and "<<y<<" respectively."<<endl;
+
+
+    return 0;
+};