Objects First with Java: A Practical Introduction Using BlueJ (6th Edition)
6th Edition
ISBN: 9780134477367
Author: David J. Barnes, Michael Kolling
Publisher: PEARSON
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Textbook Question
Chapter 3, Problem 9E
What error message do you see in the Code Pad if you type the following?
The error message is not actually very helpful at all. Can you work out what is incorrect about this call to setValue, and correct it? It would also be worth remembering this error message because it results from an easy error to make in the early stages of learning.
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Whentheuserenters!!,themostrecentcommandinthehistoryisexecuted.In the example above, if the user entered the command:
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4
1
3
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3
2
4
Data analysis
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2
5
Logical design
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c. Using the information from part b, prepare a network diagram. Identify the critical path.
2. UNIX Shell and History Feature [20 points]
This question consists of designing a C program to serve as a shell interface that
accepts user commands and then executes each command in a separate process. A
shell interface gives the user a prompt, after which the next command is entered.
The example below illustrates the prompt osh> and the user's next command:
cat prog.c. The UNIX/Linux cat command displays the contents of the file
prog.c on the terminal using the UNIX/Linux cat command and your program
needs to do the same.
osh> cat prog.c
The above can be achieved by running your shell interface as a parent process.
Every time a command is entered, you create a child process by using fork(),
which then executes the user's command using one of the system calls in the
exec() family (as described in Chapter 3). A C program that provides the general
operations of a command-line shell can be seen below.
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#include
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Chapter 3 Solutions
Objects First with Java: A Practical Introduction Using BlueJ (6th Edition)
Ch. 3 - Prob. 1ECh. 3 - At what time (s) can a class diagram change? How...Ch. 3 - At what time(s) can an object diagram change? How...Ch. 3 - Write a definition of a field named tutor that can...Ch. 3 - Prob. 5ECh. 3 - Create a second NumberDisplay object with a limit...Ch. 3 - Select Show Code Pad from the View menu. Create a...Ch. 3 - What error message do you see in the Code Pad if...Ch. 3 - What error message do you see in the Code Pad if...Ch. 3 - What happens when the setValue method is called...
Ch. 3 - Prob. 11ECh. 3 - Prob. 12ECh. 3 - Which of the following expressions return...Ch. 3 - Write an expression using boolean variables a and...Ch. 3 - Write an expression using boolean variables a and...Ch. 3 - Consider the expression (a && b). Write an...Ch. 3 - Does the getDisplayValue method work correctly in...Ch. 3 - Prob. 18ECh. 3 - In Exercise 2.79 you were asked to investigate...Ch. 3 - Explain the modulo operator. You may need to...Ch. 3 - What is the result of the expression 83?Ch. 3 - Try out the expression in the Code Pad. Try other...Ch. 3 - Prob. 23ECh. 3 - Prob. 24ECh. 3 - Explain in detail how the increment method works.
Ch. 3 - Rewrite the increment method without the modulo...Ch. 3 - Open the clock-display project and create a...Ch. 3 - Prob. 28ECh. 3 - Prob. 29ECh. 3 - Prob. 30ECh. 3 - Look at the second constructor in C1ockDisplay's...Ch. 3 - Prob. 32ECh. 3 - Given a variable Printer p1; which currently holds...Ch. 3 - Open the house project from Chapter 1 and review...Ch. 3 - Prob. 35ECh. 3 - Does the Picture class contain any internal method...Ch. 3 - Remove the following two statements from the draw...Ch. 3 - Prob. 38ECh. 3 - Prob. 39ECh. 3 - Assume a class Tree has a field of type Triangle...Ch. 3 - Prob. 41ECh. 3 - Open the mail-system project, which you can find...Ch. 3 - Prob. 43ECh. 3 - Prob. 44ECh. 3 - Open the editor for the MailClient class and set a...Ch. 3 - Step one line forward in the execution of the...Ch. 3 - Prob. 47ECh. 3 - Prob. 48ECh. 3 - Prob. 49ECh. 3 - Set a breakpoint in the first line of the sendMai1...Ch. 3 - Use a combination of code reading, execution of...Ch. 3 - Use the debugger to investigate the clock-display...Ch. 3 - Prob. 53ECh. 3 - Prob. 54ECh. 3 - Prob. 55ECh. 3 - Describe the changes that would be required to the...Ch. 3 - Write the code for the timeTick method in...Ch. 3 - Discuss whether the current design of the...Ch. 3 - Challenge exercise In the current design of...
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