Java Basic Level
In this part, you will have 20 minutes to finish 30 multiple-choice questions.
1. How many methods does the MouseMotionListener interface define
A) 2
B) 5
C) 10
D) 7
2. A skeleton is
A) A thread, which has been created, but not yet started
B) A base class, which can be extended to make a complete application
C) The definition of an object, which will be used on a server via RMI
D) A thread, which is no longer accessible from the main method
3. Java is
A) A set of programmer's libraries
B) A programming language
C) A widget set for programmers
D) A network service
4. What would I use a StringBuffer for
A) StringBuffers are deprecated; arrays of characters should be used instead
B) For reading in a line so I don't have to handle it byte-by-byte
C) Building up and manipulating a character string that needs to be changed dynamically
D) Writing text efficiently to a network so that it's not sent byte-by-byte
5. System.out.print('\u0066'); will display on your screen:
A) Capital Epsilon
B) The digit "6"
C) Lower case "o" with an Umlaut
D) A lowercase letter "f"
6. RMI is
A) A way of having a Java program or applet on one computer use Java methods and objects that are residing on another computer
B) The recommended way of having multiple invocations of the same program running on a single system
C) A Java application for remote access to Microsoft servers via the Internet
D) The pre-cursor of Java, now largely superceded
7. Which of these is a reserved word in Java
A) while
B) when
C) which
D) what
8. To find how wide a character string will appear in your AWT window, use
A) the getWidth method on a FontMetrics object
B) multiple calls to the charWidth method on a FontMetrics object
C) the stringWidth method on a FontMetrics object
D) the getLength method on a FontMetrics object
9. What value is left in the variable ttimes after running this code
String Quiz = "Some test text";
int ttimes = 0;
for (int stepper=0; stepper<Quiz.length()-1; stepper++)
if (Quiz.charAt(stepper) == 't') ;
&bsp;++ttimes;
A) 4
B) 11
C) 3
D) 12
E) 0
F) 13
H) 1
I) 2
J) 5
10. A class file is
A) A file that contains a section of compiled Java code which, with other class files, can be used to run a Java application
B) A file that contains a set of security rules to ensure that Java can't be used to distribute viruses
C) A file that is written by trainees on our courses
D) A file that contains a library of methods and objects
11. Threads are used
A) Only to hold the seams in the programmer's trousers
B) As a debugging tool to allow the programmer to trace back once a Java program has completed its operation
C) To maintain multiple contexts
D) To allow a Java program to do several things at the same time
12. What is sent to System.out by this code
int val = 11;
System.out.print("Result: "+val+1);
A) 111
B) 11
C) 12
13. the statement int [] counts = new int [26];
A) Creates a pointer to an integer array, but doesn't actually allocate any memory for it. A maximum size of 26 numbers is set for later use
B) Creates an array object that can hold up to 26 whole numbers
C) Creates an array object, initially with enough memory allocated to hold 26 numbers. But this will be extended automatically if you go past the end of the array
D) Creates an array object that can hold up to 27 whole numbers (positions 0 through 26)
14. An applet is
A) A piece of Java running within a web browser
B) An application which isn't invoked directly by the user, but is called up from within another application as, and when, required
C) A short application program which resides completely in a single file
D) A piece of Java which is only allowed to produce graphic output and cannot write to the screen in any other way
15. Which of the following is a Java primitive variable type
A) Integer
B) int
C) integer
16. A Java program typically runs
A) Faster than a program written in a shell script language, but slower than a program in a native language such as C
B) Faster than anything else on the same computer
C) About the same speed as a program written in a native language such as C, and much faster than a shell script
D) Slower than programs in shell script languages, but with modern computers that isn't a problem
17. How many interfaces can you implement in a new class at one time
A) Java does not set a limit
B) 1
C) 2 (one via "implement" and one via "extend")
D) None
18. If you extend a class, you are
A) allocating more memory to the class
B) creating extra instances of the class
C) creating a subclass
D) making a class more generic
19. If you want to print a number out to two decimal places, you would use
A) The method System.out.Printf
B) A tokenizer
C) A decimalFormat object
D) the setCurrency method with a single parameter of type float or double
20. In order to use a bean, you need access to
A) The .class file for the bean
B) A .java file for the bean
C) A beanbox, such as Sun's BDK
D) A secure connection to a server, or a signed certificate
21. Which of these is a predefined colour
A) Color.teal
B) Color.darkGray
C) Color.grey
D) Color.fuschia
22. Resource bundles are a convenient way to
A) Collect settings together for database access, so that you don't have to keep respecifying unchanged parameters for each SQL query
B) Group AWT components so that they're laid out neatly on the screen
C) Translate messages, keystrokes, short cuts, etc into a variety of different languages
D) Obtain classes for use in your Java programs, knowing they'll be written to a specific standard. It's also a good way to encourage others to reuse your classes
23. In order to distribute Java applets, you require
A) A Java-enabled web server
B) The applet in .class format
C) A licensed copy of the Java Development Kit, which comes with the appropriate rights for any programs you create using it
D) A Unix or Linux workstation which (in practice) would have a permanent link to the internet
24. An exception is always
A) generated if you try to write to STDOUT in an applet
B) an instance of class Throwable
C) flagged by the compiler
D) used to indicate that your program has failed to work correctly
25. Which of these is NOT a simple data type
A) boolean
B) String
C) double
D) byte
26. In order to move smoothly from one graphics frame to the next, you need
A) to use java.awt.zbuffer rather than java.awt.graphics components
B) to draw to an offscreen canvas and then copy the canvas in a single call to the drawImage method
C) to be able to "undraw" moving objects from their old position on the screen just before you redraw them in their new position
D) a "double buffered" frame buffer card
27. In order to store an object directly in a file, it must be
A) Transient
B) Serialisable
C) Either Public or Protected
D) Synchronised
28. Untrusted code (i.e. that has been downloaded by a browser) can ONLY do one of the following. Which
A) Read the os.name system property to find the name of the operating system it is running on
B) Read the user.name system property so that it can address the user by name
C) Read files which are marked as publicly readable from the local file system
D) Create directories
29. If I want to compare the two strings in the variables "one" and "two" to see if the contents of the strings are identical, which do I write
A) if (one.equals(two))
B) if (one == two)
C) if (one eq two)
D) if ((one-two) == 0)
30. How do you obtain the IP address of the machine your Java program is running on
A) Use the getHostbyNumber() method on a String object, where the string contains the word "localhost".
B) Use the NameService.getClient() method
C) Use the InetAddress.getLocalHost() method
D) Use the host.number System Property directly
这个参考答案不一定正确,因为是多选题:
1.a 2.c 3.b 4.c 5.f
6.c 7.a 8.a 9.c 10a
11.d 12.a 13.a,14 15b
16d 17a 18d 19c 20.a
21.b 22.a 23c 24d 25b
26.b 27b 28a 29a 30c