ssd3选择题题库

1、SSD3 选择题题库method must exist in every Java application(a) begin(b) paint(c) init(d) mainCorrect answer is (d)2 Which of the following is a valid character.literal in Java(a) ;(b) =(c) (d) aCorrect answer :AJava identifier may begin with all but which of the following(a) $(b) if(c) _ (the underscore)(

2、d) 0Correct answer is (d)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 of comments into Javadoc comments(d) automatic return of memory to the

3、heap for objects no longer required by the programCorrect answer is (d)will be output when the following Java program segment is executedint x = 5;int y = 2;5+2(b) 5 2(c) 7(d) 52Correct answer is (c)5. Which of the following parts of an if-else-statement is optional(a) the if part(b) the else part(c

4、) the parenthesis around the condition(d) the conditionCorrect answer is (b)of the following is the Java loop construct typically used when the range is clear(a) while-loop(b) for-loop(c) switch-loop(d) do-while-loopCorrect answer is (b)the following Java program segment.import .*;public class Test

5、public Test( ) default);public Test( int i ) non-default);public static void main(String args) Test 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

6、by the line of text non-default(c) The line of text default(d) The line of text non-defaultCorrect answer is (d)is the name of the JDK program that processes Javadoc comments(a) java(b) javac(c) javacom(d) javadocCorrect answer is (d)to the Java code conventions, files longer than lines should be (a

7、) 100, encouraged(b) 100, avoided(c) 2000, avoided(d) 2000, encouragedCorrect answer is (c)primitive floating-point types available in Java are and .(a) real, double(b) float , double(c) real , float(d) single , realCorrect answer is (b)many bytes are required to represent a Unicode character(a) Fou

8、r(b) One(c) Three(d) TwoCorrect answer is (d)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) (i + j);(a) 12(b) 6(c) 10(d) 8Correct answer is (d)many lines of output will be produced by the following code fragmentfor (int i = 0;

9、i 3; +i) for (int j = 0; j i; +j) (i + j); (a) 6(b) 4(c) 3(d) 5Correct answer is (c)of the following statements about class variables in Java is not true(a) Class variables require the modifier static in the declarations.instantiatedin the same(b) All objects have their own copy of the class variabl

10、e defined in the class.(c) Non-static methods in a class can access the class variable defined class.(d) Class variables do not need the reference to the object of the instantiated class to access them.Correct answer is (b)term class variable is a synonym for(a) an instance variable(b) a read-only v

11、ariable(c) a private data field(d) a static data fieldCorrect answer is (d)of the following patterns of characters opens a Javadoc comment block(a) /*(b)int x = 5;int y = 2;+ 1 + y);Which of the following statements is true about the program segment(a) The output caused by the code will be 512.(b) T

12、he output caused by the code will be 8.(c) The code will cause a compilation error.(d) The output caused by the code will be 5 1 2.Correct answer is (a)the following Java program segment.import .*;public class SomeClasspublic void x() throw new RuntimeException(Exception from x);public void y()throw

13、 new IOException(Exception from y);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

14、has a legal definition.Correct answer is (c)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)a typical debugger encounters a breakpoint, the programmer using the debugger may perform which of the followin

15、g actions1. Examine 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)name of a Java source file(a) must use the extension .class(b) must be the same as the cl

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

17、w 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 not Correct answer is (a)is the right way to handle abnormalities in input on Java(a) By

18、 handling these problems by providing exception handlers(b) By always specifying the throws clause in every method header where file I/Ois performed(c) By using the class FileFilter which gracefully filters out bad input data(d) By writing while loops to guard against bad inputCorrect answer is (a)J

19、ava exception classes are derived from the class(a) answer is (b)of the following statements is true of the conventions outlined by Sun Microsystems in the document entitled Code Conventions for the Java Programming Language1. They define a standard interface definition language that must be used fo

20、r allJava classes.2. They provide recommendations intended to make source code easier to read and understand.3. They describe one mechanism for network communication between Java and C+ programs.(a) III only(b) I, II, and III(c) II only(d) I and III onlyCorrect answer is (c)tool that allows programm

21、ers to execute lines of a program one line at a time inorder to help locate the source of a programs errors is known as a(n)(a) debugger(b) stack trace(c) exception handler(d) scopeCorrect answer is (a)of the following is not true concerning objects and their representation(a) objects are represente

22、d by their addresses(b) objects are represented by value(c) objects are represented by reference(d) objects are represented indirectlyCorrect answer is (b)programming, a loop is generally used to achieve(a) branching(b) succession(c) repetition(d) selectionCorrect answer is (c)a class contains a con

23、structor, that constructor will be invoked(a) each time an object of that class goes out of scope(b) once at the beginning of any 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) of t

24、he following categorizations can be applied to both the data fields and the methods in a Java class(a) native and non-native(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

25、 code havethe suffix , and compiled bytecode files have the suffix .(a) .javac, .class(b) .java, .class(c) .class, .javac(d) .class, .javaCorrect answer is (b)of primitive types are also referred to as(a) references(b) classes(c) objects(d) scalarsCorrect answer is (d)on the following declaration, w

26、hat does b1 represent just after the declarationis executedButton b1;(a) a default Button 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)

27、 false(c) null(d) voidCorrect answer is (d)is the name of the wrapper class for 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 statementIt does not incur run-time overhead.It can

28、 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 segmentString name = Elvis;+ was here);(a) Elviswas here(b) name was here(c) Elvis was here(d) name + was hereCorrect a