SSD3选择题题库

1、SSD3选择题题库1 .Which method must exist in every Java application?(a) begin(b) paint(c) init(d) mainCorrect answer is (d)Which of the following is a valid character literal in Java?(a) ''(b) '<='(c) "'"(d) "a"Correct answer :A2 .A Java identifier may begin with

2、 all but which of the following?(a) $(b) if(c) _ (the underscore)(d) 0Correct answer is (d)3.In the context of Java programming, garbage collection refers to(a) automatic balancing of parenthesis performed by some editors(b) removal of Java programs that could cause damage to a system(c) conversion

3、of comments into Javadoc comments(d) automatic return of memory to the heap for objects no longer required by the programCorrect answer is (d)(e) hat will be output when the following Java program segment is executed? int x = 5;int y = 2;System.out.println(x+y);(a) 5+2(b) 5 2(c) 7(d) 52Correct answe

4、r is (c)5. Which of the following parts of an if-else-statement is optional?(a) the if part(b) the else part(c) the parenthesis around the condition(d) the conditionCorrect answer is (b)6.Which of the following is the Java loop construct typically used when the range is clear?(a) while-loop(b) for-l

5、oop(c) switch-loop(d) do-while-loopCorrect answer is (b)8 .Consider the following Java program segment.import java.io.*;public class Test public Test( ) System.out.println("default");public Test( int i ) System.out.println("non-default");public static void main(String args) Test

6、t = new Test(2);Which of the following will be output during execution of the program segment?(a) The line of text "non-default" followed by the line of text "default"(b) The line of text "default" followed by the line of text "non-default"(c) The line of text

7、 "default"(d) The line of text "non-default"Correct answer is (d)9 .What is the name of the JDK program that processes Javadoc comments?(a) java(b) javac(c) javacom(d) javadocCorrect answer is (d)10 .According to the Java code conventions, files longer than lines shouldbe .(a) 10

8、0, encouraged(b) 100, avoided(c) 2000, avoided(d) 2000, encouragedCorrect answer is (c)2 .The primitive floating-point types available in Java are and .(a) real, double(b) float , double(c) real , float(d) single , realCorrect answer is (b)3 .How many bytes are required to represent a Unicode charac

9、ter?(a) Four(b) One(c) Three(d) TwoCorrect answer is (d)5 .How many lines of output will be produced by the following code fragment?for (int i = 0; i < 4; +i) for (int j = 1; j < 3 ; +j) stdOut.println(i + j);(a) 12(b) 6(c) 10(d) 8Correct answer is (d)6 .How many lines of output will be produc

10、ed by the following code fragment?for (int i = 0; i < 3; +i) for (int j = 0; j < i; +j) stdOut.println(i + j);(a) 6(b) 4(c) 3(d) 5Correct answer is (c)7 .Which of the following statements about class variables in Java is not true?(a) Class variables require the modifier static in the declarati

11、ons.(b) All objects have their own copy of the class variable defined in the instantiated class.(c) Non-static methods in a class can access the class variable defined in the same class.(d) Class variables do not need the reference to the object of the instantiated class to access them.Correct answe

12、r is (b)8 .The term class variable is a synonym for(a) an instance variable(b) a read-only variable(c) a private data field(d) a static data fieldCorrect answer is (d)9 .Which of the following patterns of characters opens a Javadoc comment block?(a) /*(b) /(c) /*(d) */Correct answer is (a)2 .The ter

13、m wrapper classes refers to(a) the Java classes that contain at least two data fields(b) the Java classes that contain themselves(c) a collection of Java classes that "wrap" Java primitive types(d) a collection of Java classes that contain other Java classesCorrect answer is (c)3 .Given th

14、e following code, what value will be output by the last statement?StringTokenizer st = new StringTokenizer("this is,a,test of tokens", ",");String s;int count = 0;while (st.hasMoreTokens() s = st.nextToken();+count;stdOut.println(count);(a) 3(b) 1(c) 6(d) 4Correct answer is (a)5

15、.Consider the following Java program x = 5;int y = 2;System.out.println(x + "1" + y);Which of the following statements is true about the program segment?(a) The output caused by the code will be 512.(b) The output caused by the code will be 8.(c) The code will cause a compilati

16、on error.(d) The output caused by the code will be 5 1 2.Correct answer is (a)6 .Consider the following Java program segment.import java.io.*;public class SomeClasspublic void x() throw new RuntimeException("Exception from x");public void y()throw new IOException("Exception from y&quo

17、t;);Which of the following is true concerning the definitions for the methods x and y?(a) Neither x nor y has a legal definition.(b) Both x and y have legal definitions.(c) x has a legal definition, but y has an illegal definition.(d) x has an illegal definition, but y has a legal definition.Correct

18、 answer is (c)7.1 n Java, exceptions that are not handled are passed up the(a) exception ladder(b) call stack(c) catch blocks(d) block hierarchyCorrect answer is (b)10.After a typical debugger encounters a breakpoint, the programmer using the debugger may perform which of the following actions?1. Ex

19、amine the values of variables in the halted program2. Execute the current line3. Resume execution of the halted program(a) III only(b) I, II, and III(c) I only(d) I and II onlyCorrect answer is (b)1 .The name of a Java source file(a) must use the extension .class(b) must be the same as the class it

20、defines, respecting case(c) must be the same as the class it defines, ignoring case(d) has no restrictionsCorrect answer is (b)5 .A difference between the methods print and println of the class java.io.PrintWriter is that(a) println appends a new line to the end of its output, but print does not(b)

21、print appends a new line to the end of its output, but println does not(c) println inserts a new line at the beginning of its output, but print does not(d) print inserts a new line at the beginning of its output, but println does notCorrect answer is (a)6 .What is the right way to handle abnormaliti

22、es in input on Java?(a) By handling these problems by providing exception handlers(b) By always specifying the throws clause in every method header where fileI/O is performed(c) By using the class FileFilter which gracefully filters out bad input data(d) By writing while loops to guard against bad i

23、nputCorrect answer is (a)7 .All Java exception classes are derived from the class(a) java.lang.RuntimeException(b) java.lang.Throwable(c) java.lang.Error(d) java.io.IOExceptionCorrect answer is (b)9.Which of the following statements is true of the conventions outlined by Sun Microsystems in the docu

24、ment entitled Code Conventions for the Java Programming Language?1. They define a standard interface definition language that must be used for all Java classes.2. They provide recommendations intended to make source code easier to read and understand.3. They describe one mechanism for network commun

25、ication between Java and C+ programs.(a) III only(b) I, II, and III(c) II only(d) I and III onlyCorrect answer is (c)10.A tool that allows programmers to execute lines of a program one line at a time in order to help locate the source of a program's errors is known as a(n)(a) debugger(b) stack t

26、race(c) exception handler(d) scopeCorrect answer is (a)2.Which of the following is not true concerning objects and their representation?(a) objects are represented by their addresses(b) objects are represented by value(c) objects are represented by reference(d) objects are represented indirectlyCorr

27、ect answer is (b)5.In programming, a loop is generally used to achieve(a) branching(b) succession(c) repetition(d) selectionCorrect answer is (c)7.If a class contains a constructor, that constructor will be invoked(a) each time an object of that class goes out of scope(b) once at the beginning of an

28、y program that uses that class(c) once the first time an object of that class is instantiated(d) each time an object of that class is instantiatedCorrect answer is (d)8.Which of the following categorizations can be applied to both the data fields and the methods in a Java class?(a) native and non-na

29、tive(b) static and non-static(c) default and non-default(d) abstract and non-abstractCorrect answer is (b)10. According to the Java code conventions, files that contain Java source code have the suffix , and compiled bytecode files have the suffix .(a) .javac, .class(b) .java, .class(c) .class, .jav

30、ac(d) .class, .javaCorrect answer is (b)2.Variables of primitive types are also referred to as(a) references(b) classes(c) objects(d) scalarsCorrect answer is (d)3.Based on the following declaration, what does b1 represent just after the declaration is executed?Button b1;(a) a "default" Bu

31、tton object(b) a Button object with no label(c) a blank Button object(d) nothingCorrect answer is (d)8. The return type for a method that returns nothing to its caller is(a) not specified in the method definition(b) false(c) null(d) voidCorrect answer is (d)2.What is the name of the wrapper class fo

32、r the type int?(a) Integer(b) INT(c) integer(d) IntCorrect answer is (a)3. Which of the following statements is (are) true about the use of an asterisk (*) in a Java import statement?It does not incur run-time overhead.It can be used to import multiple packages with a single statement.It can be used to import multiple classes with a single statement.(a) III only(b) I and III only(c) I only(d) I, II, and IIICorrect answer is (b)4. What will be output caused by the execution of the following Java program segment?String name = "Elvis"System.out.print(name +