1、19JAVA程序员笔试题目与答案1.Given: Integer i = new Integer (42);Long l = new Long (42);Double d = new Double (42.0); Which two expressions evaluate to True?A. (i == 1)B. (i == d)C. (d == 1)D. (i.equals (l))E. (d.equals (l))F. (i.equals (42)) G. none of aboveAnswer: 2. Given: public class Foo {
2、 public static void main (String [] args) { StringBuffer a = new StringBuffer("A"); StringBuffer b = new StringBuffer ("B"); operate (a,b); System.out.println(a + "," +b);19 } static void operate(StringBuffer x, StringBuffer y) { x.append(y); y =
3、 x; }}What is the result? A. The code compiles and prints “A,B”.B. The code compiles and prints “A,A”.C. The code compiles and prints “B,B”.D. The code compiles and prints “AB,B”.E. The code compiles and prints “AB,AB”.F. The code does not compile because “+” cannot be overloaded for StringBu
4、ffer. Answer: 3.Given:class BaseClass { private float x = 1.0f ; protected float getVar() {return x;}}19class Subclass extends BaseClass { private float x = 2.0f; //insert here}Which two are valid examples of method overriding?A. float getVar() { return x;}B. public float ge
5、tVar() { return x;}C. public double getVar() { return x;}D. protected float getVar() { return x;}E. public float getVar(float f) { return f;}Answer: 4. Which of the following are methods of the Runnable interfaceA) runB) startC) yieldD) stopAnswer: 5. Which of the following ar
6、e legal statements?A) float f=1/3;B) int i=1/3;19C) float f=1.01;D) double d=999d;Answer: 6. Given:public class test( public static void main(string[] args){ String foo = args[1]; String baz = args[2]; String bax = args[3]; }} And the command line invoc
7、ation: Java Test red green blue What is the result? A. baz has the value of “”B. baz has the value of nullC. baz has the value of “red”D. baz has the value of “blue”E. bax has the value of “green”F. the code does not compile
