Lab 2 for CIS 67

1.  Take program coins.cpp (the original version) and make the following 
modifications:

Write a function named coins_instruct and place it after your main function.

void coins_instruct()
{

   ... put some instructions for the user in here. See Fig. 3.17 for
       example.
}

Insert the function prototype line:

void coins_instruct();

before your main function and insert a call to this function

coins_instruct();

at the beginning of your main function - before you read in the user's name.

2. Write 3 one-line functions that have these  prototypes:

   //Calculates and returns the total value (in cents)  of the coins 
   //for a given amount of pennies, nickles 
   //(the function arguments)
   int calc_coins_value(int, int);

   //Calculates the dollars for a given value in cents (the argument)
   int calc_dollars(int);

   //Calculates the change value (cents) for a given amount in cents
   int calc_change(int);

   As an example, the function cacl_dollars would be:

   int calc_dollars(int total_cents)
   {
      return total_cents / 100;
   }

  a.  Place the 3 prototypes before function main.
  b.  Place the 3 functions after function main.

  c.  Replace the expression part of each assignment statement in your main
      function with a call to one of these functions. For example,

  dollars = calc_dollars(total_cents);

  d.  Compile, build, and run the final program.

3.  Explain how function calc_coins_value "gets its input".
    Explain what happens to the value returned by calc_coins_values - 
    the function output. 
    What type of data does C++ expect calc_coins_value to return and 
     what type of data does the function expect as its inputs? How do
     you think C++ knows this.

4.  Read one of the documents on my home page about the
    C++ debugger and try stepping through this program 1 line at a time
    using  the debugger. Click on the Locals tab and
    Observe how the variables in the watch window change as you go in and
    out of each function. Click the icon for step over {}! when the next
    line to execute (indicated by yellow arrow) begins with cin or cout.
    For all other lines, click the icon for step into {!}.

    What are the names of the local variables in a watch window during each
    function execution? Answer this for all functions including main.

5. Assignment due before lab next week. Turn in program and sample 
   run after it has been modified to use functions. Give answers to 
   questions in 3 and 4 above.
   Also, do programming project #9, p. 225. I recommend you
   use a switch statement to select the statements to execute based on the
   user code. 
   Each case of the switch should calculate the bill for that kind of 
   user. For code 'c' and 'i', you will need if statements to calculate
   the bill.