2015桂电JAVA题库重点(含答案翻译).doc

1、 Which of the following is not a valid Java identifier? A. my Value B. $_AAA1 C. width D. m_x 2、 Sending a message to an object means that: A. You call a method of the object.你对象的调用一个方法。 B. You access a variable of the object. C. Both (a) and (b). D. Neither (a) nor (b). 3、 Which of the following is a Scanner method? A. nextLine. B. nextText. C. nextWord. D. readNext. 4、 Which is a correct static method call of Math class method sqrt? A. sqrt( 900 );. B. math.sqrt( 900 );. C. Math.sqrt( 900 );. D. Math math = new Math(); math.sqrt( 900 );. 5、 Declaring main as ________ allows the JVM to invoke main without creating an instance of the class. A. public. B. void. C. static. D. final. 6、 Consider the array: s[ 0 ] = 7s[ 1 ] = 0s[ 2 ] = -12s[ 3 ] = 9s[ 4 ] = 10s[ 5 ] = 3s[ 6 ] = 6 The value of s[s[6]-s[5]] is: A. 0. B. 3. C. 9. D. 10. 7、 What do the following statements do? double[] array;array = new double[ 14 ]; A. Create a double array containing 13 elements. B. Create a double array containing 14 elements.创建一个数组包含14个元素的两倍。 C. Create a double array containing 15 elements. D. Declare but do not create a double array. 8、 The _________ of a class are also called the public services or the public interface that the class provides to its clients. A. public constructors. B. public instance variables. C. public methods. D. All of the above. 9、 Using public set methods provides data integrity if: A. The instance variables are public.实例变量是公开的。 B. The instance variables are private. C. The methods perform validity checking.执行有效性检查的方法 D. Both b and c. 10、 Which of the following keywords allows a subclass to access a superclass method even when the subclass has overridden the superclass method? A. base. B. this. C. public. D. super. 11、 Which method changes the text the label displays? A. changeText. B. setText. C. changeLabel. D. setLabel. 12、 A(n) class cannot be instantiated.类不能被实例化。 A. final. B. concrete. C. abstract. 抽象的， D. polymorph