Sams Teach Yourself C++ in 21 Days

20: int a, b, c;

21: cout << “Enter two numbers: “;

22: cin >> a;

23: cin >> b;

24:

25: cout << “\nCalling Add()\n”;

26: c=Add(a,b);

27: cout << “\nBack in main().\n”;

28: cout << “c was set to “ << c;

29:

30: cout << “\n\nCalling Subtract()\n”;

31: c=Subtract(a,b);

32: cout << “\nBack in main().\n”;

33: cout << “c was set to “ << c;

34:

35: cout << “\nExiting...\n\n”;

36: return 0;

37: }

Day 3....................................................................................................................

Quiz ................................................................................................................

1. Integer variables are whole numbers; floating-point variables are “reals” and have a
   “floating” decimal point. Floating-point numbers can be represented using a man-
   tissa and exponent.


2. The keyword unsignedmeans that the integer will hold only positive numbers. On
   most computers with 32-bit processors,shortintegers are two bytes and longinte-
   gers are four. The only guarantee, however, is that a longinteger is at least as big
   or bigger than a regular integer, which is at least as big as a shortinteger.
   Generally, a longinteger is twice as large as a shortinteger.


3. A symbolic constant explains itself; the name of the constant tells what it is for.
   Also, symbolic constants can be redefined at one location in the source code, rather
   than the programmer having to edit the code everywhere the literal is used.
   4.constvariables are “typed,” and, thus, the compiler can check for errors in how
   they are used. Also, they survive the preprocessor, and, thus, the name is available
   in the debugger. Most importantly, using #defineto declare constants is no longer
   supported by the C++ standard.


4. A good variable name tells you what the variable is for; a bad variable name has
   no information. myAgeand PeopleOnTheBusare good variable names, but x,xjk,
   and prndlare probably less useful.


5. BLUE= 102

824 Appendix D

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