C++ Primer Plus (Six Edition) Chapter 2, Review

Q1. What are the modules of C++ programs called?

A:   Founctions.

Q2. What does the following preprocessor directive do?

      #include <iostream>

A: It causes the contents of the iostream file to be substituted for this directive before final compilation.

Q3. What does the following statement do?

       using namespace std;

A:  It makes definitions made in the std namespace available to a program.

Q4. What statement would you use to print the phrase "Hello,world" and then start a newline?

A:cout << "Hello, world" << endl;

   or 

   cout << "Hello,world\n";

Q5. What statement would you use to creat an integer variable with the name cheeses?

A:int cheese;

Q6. What statement would you use to assign the value 32 to the variable cheeses?

A:cheeses = 32;

Q7. What statement would you use to read a value from keybord input into the variable cheeses?

A:cin >> cheeses;

Q8. What statement would you use to print "We have X varieties of cheese," where the current value of the cheeses variable repliaces X?

A:cout << " We have <<" cheeses" << varieties of cheese" endl;

Q9. What do the following function prototypes tell you about the functions?

       int froop(double t);

       void rattle(int n);

       int prune(void);

A:The first one, the function froop() expects to be called with one argument, which will be type double, and that the function will return a type int value. For instance, it

           could be used as follows:          int gval = froop(3.14159);

   The second one, the function rattle() has no return value and expects an int argument. For instance, it could be used as follows:   rattle(37);

   The third one, the function prune() returns an int and expects to be used without an argument. For instance, it could be used as follows:

           int residue = prune();

Q10. When do you not have to use the keyword return when you define a function?

A: You don't have to use return in a function when the function has the return type void. However, you can use it if you don't give a return value:     return;

Q11. Suppose your main() function has the following line:   (Note:The answer following is given by myself, and it may not be very precise!)

         cout  << "Please enter your PIN: ";

         And suppose the complier complains that cout is an unkown identifier. What is the likely cause of  this complaint, and what are three ways to fix the problem?

A:     The likely cause it that the function loses a  statement " using namespace std;" to declare a directive of output.

         place "using  namespace std;" above the main() function;

         place"using  std::cout; in the main() function;

         type as following:" std::cout << " Please enter your PIN: " << std::endl;

                        THANK YOU!!