Line 4 of class Target can be changed to return i++;
Line 2 of class Target can be changed to private int i = 1;
Line 3 of class Target can be changed to private int addOne() {
Line 2 of class Target can be changed to private Integer i = 0;
第1题:
1. public class Target { 2. private int i = 0; 3. public int addOne() { 4. return ++i; 5. } 6. } And: 1. public class Client { 2. public static void main(String[] args) { 3. System.out.println(new Target().addOne()); 4. } 5. } Which change can you make to Target without affecting Client?()
第2题:
Which are syntactically valid statement at// point x?() class Person { private int a; public int change(int m){ return m; } } public class Teacher extends Person { public int b; public static void main(String arg[]){ Person p = new Person(); Teacher t = new Teacher(); int i; // point x } }
第3题:
1. public class X { 2. public static void main (String[]args) { 3. int [] a = new int [1] 4. modify(a); 5. System.out.printIn(a[0]); 6. } 7. 8. public static void modify (int[] a) { 9. a[0] ++; 10. } 11. } What is the result?()
第4题:
1. public class Test { 2. public static String output =””; 3. 4. public static void foo(int i) { 5. try { 6. if(i==1) { 7. throw new Exception(); 8. } 9. output += “1”; 10. } 11. catch(Exception e) { 12. output += “2”; 13. return; 14. } 15. finally { 16. output += “3”;17. } 18. output += “4”; 19. } 20. 21. public static void main(String args[]) { 22. foo(0); 23. foo(1); 24. 25. }26. } What is the value of the variable output at line 23?()
第5题:
Given classes defined in two different files: 1. package util; 2. public class BitUtils { 3. private static void process(byte[] b) { } 4. } 1. package app; 2. public class SomeApp { 3. public static void main(String[] args) { 4. byte[] bytes = new byte[256]; 5. // insert code here 6. } 7. } What is required at line 5 in class SomeApp to use the process method of BitUtils?()
第6题:
1. public class enclosingone ( 2. public class insideone{} 3. ) 4. public class inertest( 5. public static void main (string[]args)( 6. enclosingone eo= new enclosingone (); 7. //insert code here 8. ) 9. ) Which statement at line 7 constructs an instance of the inner class?()
第7题:
1. public class test ( 2. public static void main(string args[]) { 3. int 1= 0; 4. while (i) { 5. if (i==4) { 6. break; 7. } 8. ++i; 9. } 10. 11. } 12. ) What is the value of i at line 10?()
第8题:
Compilation will succeed for all classes and interfaces.
Compilation of class C will fail because of an error in line 2.
Compilation of class C will fail because of an error in line 6.
Compilation of class AImpl will fail because of an error in line 2.
第9题:
Value is: 8
Compilation fails.
Value is: 12
Value is: -12
The code runs with no output.
An exception is thrown at runtime.
第10题:
test
null
An exception is thrown at runtime.
Compilation fails because of an error in line 1.
Compilation fails because of an error in line 4.
Compilation fails because of an error in line 5.
第11题:
import utils.*;
static import utils.*;
import utils.Repetition.*;
static import utils.Repetition. *;
import utils.Repetition.twice();
import static utils.Repetition.twice;
static import utils.Repetition.twice;
第12题:
Class A
Compilation fails.
An exception is thrown at line 2.
An exception is thrown at line 6.
The code executes with no output.
第13题:
1. public interface A { 2. public void doSomething(String thing); 3. } 1. public class AImpl implements A { 2. public void doSomething(String msg) { } 3. } 1. public class B { 2. public A doit() { 3. // more code here 4. } 5. 6. public String execute() { 7. // more code here 8. } 9. } 1. public class C extends B { 2. public AImpl doit() { 3. // more code here 4. } 5. 6. public Object execute() { 7. // more code here 8. } 9. } Which statement is true about the classes and interfaces in the exhibit?()
第14题:
1. public class A { 2. void A() { 3. System.out.println(“Class A”); 4. } 5. public static void main(String[] args) { 6. new A(); 7. } 8. } What is the result?()
第15题:
class Super { public int i = 0; public Super(String text) { i = 1; } } public class Sub extends Super { public Sub(String text) { i = 2; } public static void main(String args[]) { Sub sub = new Sub(“Hello”); System.out.println(sub.i); } } What is the result?()
第16题:
public class Test { public int aMethod() { static int i = 0; i++; return i; } public static void main (String args[]) { Test test = new Test(); test.aMethod(); int j = test.aMethod(); System.out.println(j); } } What is the result?()
第17题:
Given classes defined in two different files: 1. package util; 2. public class BitUtils { 3. public static void process(byte[]) { /* more code here */ } 4. } 1. package app; 2. public class SomeApp { 3. public static void main(String[] args) { 4. byte[] bytes = new byte[256]; 5. // insert code here 6. } 7. } What is required at line 5 in class SomeApp to use the process method of BitUtils?()
第18题:
Given a class Repetition: 1. package utils; 2. 3. public class Repetition { 4. public static String twice(String s) { return s + s; } 5. } and given another class Demo: 1. // insert code here 2. 3. public class Demo { 4. public static void main(String[] args) { 5. System.out.println(twice(”pizza”)); 6. } 7. } Which code should be inserted at line 1 of Demo.java to compile and run Demo to print“pizzapizza”?()
第19题:
1. interface TestA { String toString(); } 2. public class Test { 3. public static void main(String[] args) { 4. System.out.println(new TestA() { 5. public String toString() { return “test”; } 6. } 7. } 8. } What is the result?()
第20题:
0
3
4
5
The code will not compile.
第21题:
process(bytes);
BitUtils.process(bytes);
util.BitUtils.process(bytes);
SomeApp cannot use methods in BitUtils.
import util.BitUtils.*; process(bytes);
第22题:
InsideOnew ei= eo.new InsideOn();
Eo.InsideOne ei = eo.new InsideOne();
InsideOne ei = EnclosingOne.new InsideOne();
EnclosingOne.InsideOne ei = eo.new InsideOne();
第23题:
Compilation succeeds and 1 is printed.
Compilation succeeds and 2 is printed.
An error at line 8 causes compilation to fail.
An error at line 13 causes compilation to fail.
An error at line 14 causes compilation to fail.