In this exercise, you will experiment with passing variables by value and by reference. 

a. Follow the instructions for starting C++ and viewing the TryThis9.cpp file, which is contained in either the Cpp8\Chap10\TryThis9 Project folder or the Cpp8\Chap10 folder. (Depending on your C++ development tool, you may need to open this exercise’s project/solution file first.)

b. Notice that the main function passes the age variable by value to the getAge function. Run the program. When prompted to enter your age, type your age and press Enter. The message that appears should contain your age; however, it contains the number 0 instead. This is because the age variable is passed by value to the getAge function. 

c. Modify the program so that it passes the age variable by reference to the getAge function. Save and then run the program. When prompted to enter your age, type your age and press Enter. This time, the message contains your age.