SCJP题库.doc

Exam : 310-035 Title : Sun Certified Programmer for Java 2 Platform 1.4 Ver : 06.20.06 310-035 QUESTION 1: Given: 1. public class Test { 2. public static void main(String args[]) { 3. class Foo { 4. public int i = 3; 5. } 6. Object o = (Object)new Foo(); 7. Foo foo = (Foo)o; 8. System.out.println(i = + foo.i); 9. } 10. } What is the result? A. i = 3 B. Compilation fails. C. A ClassCastException is thrown at line 6. D. A ClassCastException is thrown at line 7. Answer: A QUESTION 2: Which two cause a compiler error? (Choose two) A. float[] = new float(3); B. float f2[] = new float[]; C. float[] f1 = new float[3]; D. float f3[] = new float[3]; E. float f5[] = { 1.0f, 2.0f, 2.0f }; F. float f4[] = new float[] { 1.0f. 2.0f. 3.0f}; Answer: A, B The F. statement is incorrect. The float numbers should be separated with commas and not dots. QUESTION 3: Given: 11. int i =1,j =10; 12. do { 13. if(i++ --j) { 14. continue; 15. } A - The Power of Knowing 310-035 16. } while (i 5); 17. System.out.println(i = +i+ and j = +j); What is the result? A. i = 6 and j = 5 B. i = 5 and j = 5 C. i = 6 and j = 5 D. i = 5 and j = 6 E. i = 6 and j = 6 Answer: D MARK QUESTION 4: Given: 1. class Test { 2. private Demo d; 3. void start() { 4. d = new Demo(); 5. this.takeDemo(d); 6. } 7. 8. void takeDemo(Demo demo) { 9. demo = null; 10. demo = new Demo(); 11. } 12. } When is the Demo object, created on line 3, eligible for garbage collection? A. After line 5. B. After line 9. C. After the start() method completes. D. When the takeDemo() method completes. E. When the instance running this code is made eligible for garbage collection. Answer: E QUESTION 5: Given: 1. interface Animal { 2. void soundOff(); 3. } 4. 5. class Elephant implements Animal { 6. public void soundOff() { A - The Power of Knowing 310-035 7. System.out.println(Trumpet); 8. } 9. } 10. 11. class Lion implements Animal { 12. public void soundOff() { 13. System.out.println(Roar); 14. } 15. } 16. 17. class Alpha1 { 18. s