chap01

Answers To Non-programming Exercises

Contents

• Exercise 1.1
• Exercise 1.2
• Exercise 1.3
• Exercise 1.4
• Exercise 1.5
• Exercise 1.6
• Exercise 1.7
• Exercise 1.8
• Exercise 1.9
• Exercise 1.10
• Exercise 1.11
• Exercise 1.12
• Exercise 1.13
• Exercise 1.14
• Exercise 1.15
• Exercise 1.16
• Exercise 1.17
• Exercise 1.18
• Exercise 1.19
• Exercise 1.20
• Exercise 1.21
• Exercise 1.22
• Exercise 1.23
• Exercise 1.24
• Exercise 1.25

Exercise 1.1

Review the documentation for your compiler and determine what file naming convention it uses. Compile and run the main program from page 2.

Exer01_01.cpp

Exercise 1.2

Change the program to return -1. A return value of -1 is often treated as an indicator that the program failed. Recompile and rerun your program to see how your system treats a failure indicator from main.

Exer01_02.cpp

Exercise 1.3

Write a program to print Hello, World on the standard output.

Exer01_03.cpp

Exercise 1.4

Our program used the addition operator, +, to add two numbers. Write a program that uses the multiplication operator, *, to print the product instead.

Exer01_04.cpp

Exercise 1.5

We wrote the output in one large statement. Rewrite the program to use a separate statement to print each operand.

Exer01_05.cpp

Exercise 1.6

Explain whether the following program fragment is legal.

std::cout << "The sum of " << v1;
          << " and " << v2;
		  << " is " << v1 + v2 << std::endl;

If the program is legal, what does it do? If the program is not legal, why not? How would you fix it?

The program is illegal. It attempts to output the sum of v1 and v2, but appends surplus semicolons. The correct way:

std::cout << "The sum of " << v1
          << " and " << v2
		  << " is " << v1 + v2 << std::endl;

Exercise 1.7

Compile a program that has incorrectly nested comments.

Exer01_07.cpp

Exercise 1.8

Indicate which, if any, of the following output statements are legal:

std::cout << "/*";
std::cout << "*/";
std::cout << /* "*/" */;
std::cout << /* "*/" /* "/*" */;

After you’ve predicted what will happen, test your answers by compiling a program with each of these statements. Correct any errors you encounter.

Legal statements:

(a) std::cout << "/*";
(b) std::cout << "*/";
(d) std::cout << /* "*/" /* "/*" */;

Illegel statements:

(c) std::cout << /* "*/" */;

We can correct it as below:

(c) std::cout << /* "*/" */";

see Exer01_08.cpp

Exercise 1.9

Write a program that uses a while to sum the numbers from 50 to 100.

Exer01_09.cpp

Exercise 1.10

In addition to the ++ operator that adds 1 to its operand, there is a decrement operator (--) that subtracts 1. Use the decrement operator to write a while that prints the numbers from ten down to zero.

Exer01_10.cpp

Exercise 1.11

Write a program that prompts the user for two integers. Print each number in the range specified by those two integers.

Exer01_11.cpp

Exercise 1.12

What does the following for loop do? What is the final value of sum?

int sum = 0;
for (int i = -100; i <= 100; ++i)
    sum += i;

The for loop evaluates the sum from -100 to 100. The final value of sum is 0.

See Exer01_12.cpp

Exercise 1.13

Rewrite the exercises from § 1.4.1 (p. 13) using for loops.

Exer01_13_1.cpp | Exer01_13_2.cpp | Exer01_13_3.cpp

Exercise 1.14

Compare and contrast the loops that used a for with those using a while. Are there advantages or disadvantages to using either form?

• for loop

  for is more fit for loops that will execute known times.

• while loop

  while is more fit for loops that will execute unknown times.

Exercise 1.15

Write programs that contain the common errors discussed in the box on page 16. Familiarize yourself with the messages the compiler generates.

(nothing)

Exercise 1.16

Write your own version of a program that prints the sum of a set of integers read from cin.

Exer01_16.cpp

Exercise 1.17

What happens in the program presented in this section if the input values are all equal? What if there are no duplicated values?

If the input values are all equal, there will be only one line of output.

If there are no duplicated values, there will be as many lines of outputs as the number of input values.

See next exercise.

Exercise 1.18

Compile and run the program from this section giving it only equal values as input. Run it again giving it values in which no number is repeated.

Exer01_18.cpp

Exercise 1.19

Revise the program you wrote for the exercises in § 1.4.1 (p. 13) that printed a range of numbers so that it handles input in which the first number is smaller than the second.

Exer01_19.cpp

Exercise 1.20

http://www.informit.com/title/032174113 contains a copy of Sales_item.h in the Chapter 1 code directory. Copy that file to your working directory. Use it to write a program that reads a set of book sales transactions, writing each transaction to the standard output.

Exer01_20.cpp

Exercise 1.21

Write a program that reads two Sales_item objects that have the same ISBN and produces their sum.

Exer01_21.cpp

Exercise 1.22

Write a program that reads several transactions for the same ISBN. Write the sum of all the transactions that were read.

Exer01_22.cpp

Exercise 1.23

Write a program that reads several transactions and counts how many transactions occur for each ISBN.

Exer01_24.cpp

Exercise 1.24

Test the previous program by giving multiple transactions representing multiple ISBNs. The records for each ISBN should be grouped together.

Exer01_24.cpp

Exercise 1.25

Using the Sales_item.h header from the Web site, compile and execute the bookstore program presented in this section.

Exer01_25.cpp