java择题题库.docVIP

2. Which of the following is a valid character literal in Java? (a) ; (b) = (c)  (d) a Correct answer :A 2.A Java identifier may begin with all but which of the following? (a) $ (b) if (c) _ (the underscore) (d) 0 Correct 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 of comments into Javadoc comments (d) automatic return of memory to the heap for objects no longer required by the program Correct answer is (d) 9.What is the name of the JDK program that processes Javadoc comments? (a) java (b) javac (c) javacom (d) javadoc Correct answer is (d) 2.The primitive floating-point types available in Java are _____ and _____. (a) real, double (b) float , double (c) real , float (d) single , real Correct answer is (b) 3.How many bytes are required to represent a Unicode character? (a) Four (b) One (c) Three (d) Two Correct 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) 8 Correct answer is (d) 6.How many lines of output will be produced 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) 5 Correct 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 declarations. (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 answer is (b) 8.The term class variable is a synonym for (a) an instance vari