Answers to Chapter 4 Review Questions
-------------------------------------

6.  Conditionals & Iteration. Conditionals (switch, if) are used
    to make decisions, and Iteration (while, for) is used for
    repitition.

7.  One control statement is in the body of another control statement.
    For example:  for (i=0; i<10; i++) {
                    for (j=0; j<i; j++) {
                      statements_here;
                    }
                  }

9.  C interprets the mathematical symbol = as an assignment operator, and 
    an assignment is performed instead of a comparison.  For example, the 
    following program will print out "The if test is true, value of n is 
    now 42" because (n = 42) causes n to be assigned the value 42, which 
    then gets interpreted as TRUE by the if, since all non-zero integers are 
    considered to be equivalent to TRUE.  The proper expression to use 
    is really (n == 42)

         n = 0;
         if (n = 42) {
           printf("The if test is true, ");
         }
         printf("value of n is now %d\n", n);

11. (n >= 0) && (n <= 9)

12. (x != 4) || (x != 17) is TRUE if x is not equal to 4 OR x is
    not equal to 17. So it is FALSE if x=4 AND x=17, which can't
    ever happen. Here's a table:

            x      x!=4     x!=17    either x!=4 TRUE OR x!=17 TRUE
           ---     ----     -----    ------------------------------
            1      TRUE     TRUE       TRUE
            4      FALSE    TRUE       TRUE
            10     TRUE     TRUE       TRUE
            17     TRUE     FALSE      TRUE

14. It is redundant.  A better way to write this is just "if (myFlag) . . ."

17. It completes the current cycle first.

21. (a) for (i = 1; i <= 100; i++)
    (b) for (i = 0; i < 100; i += 7)
    (c) for (i = 100; i >= 0; i -= 2)

22. Because floating-point numbers are only approximations, and the
    precision of the machine may cause unexpected results.