The program output
The output produced by the program is shown below:
In main a = 10 b = 20.1 In aFunction x = 10 y = 20.1 Change x and y Still in aFunction x = 100 y = 200.1 Back in main a = 100 b = 20.1
The important difference
The important difference between this output and the output produced by the previous program is highlighted in boldface.
Changing the value of a parameter that was passed by reference changes the value stored in the variable that was passed by reference.