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1题:
1. public class A { 2. public void doit() { 3. } 4. public String doit() { 5. return “a”; 6. } 7. public double doit(int x) { 8. return 1.0; 9. } 10.} What is the result?()
第2题:
现有2 个文件: 1. package x; 2. public class X { 3. public static void doX() { System.out.print("doX "); } 4. } 和: 1. class Find { 2. public static void main(String [] args) { 3. //insert code here 4. } 5. } 哪两行分别插入到类Find 的第3 行将编译并产生输出“doX”? ()
第3题:
1. public class A { 2. public void method1() { 3. B b=new B(); 4. b.method2(); 5. // more code here 6. } 7. } 1. public class B { 2. public void method2() { 3.C c=new C(); 4. c.method3(); 5. // more code here 6. } 7. } 1. public class C { 2. public void method3() { 3. // more code here 4. } 5. } Given: 25. try { 26. A a=new A(); 27. a.method1(); 28. } catch (Exception e) { 29. System.out.print(”an error occurred”); 30. } Which two are true if a NullPointerException is thrown on line 3 of class C?()
第4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5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6题:
现有: 1. interface Animal { 2. void eat(); 3. } 4. 5. // insert code here 6. 7. public class HouseCat extends Feline { 8. public void eat() { } 9. } 和五个声明: abstract class Feline implements Animal { } abstract class Feline implements Animal { void eat(); } abstract class Feline implements Animal { public void eat(); } abstract class Feline implements Animal { public void eat() { } } abstract class Feline implements Animal { abstract public void eat(); } 分别插入到第5行,有几个可以通过编译?()
第7题:
No code is necessary.
throws Exception
catch ( Exception e )
throws RuntimeException
catch ( TestException e)
第8题:
Line 33 must be called within a try block.
The exception thrown by method1 in class a is not required to be caught.
The method declared on line 31 must be declared to throw a RuntimeException.
On line 5 of class a, the call to method2 of class b does not need to be placed in a try/catch block.
第9题:
The application will crash.
The code on line 29 will be executed.
The code on line 5 of class A will execute.
The code on line 5 of class B will execute.
The exception will be propagated back to line 27.
第10题:
process(bytes);
BitUtils.process(bytes);
util.BitUtils.process(bytes);
SomeApp cannot use methods in BitUtils.
import util.BitUtils.*; process(bytes);
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:
An exception is thrown at runtime.
Compilation fails because of an error in line 7.
Compilation fails because of an error in line 4.
Compilation succeeds and no runtime errors with class A occur.
第13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14题:
1. public class Exception Test { 2. class TestException extends Exception {} 3. public void runTest() throws TestException {} 4. public void test() /* Point X */ { 5. runTest(); 6. } 7. } At Point X on line 4, which code is necessary to make the code compile?()
第15题:
1. class super { 2. public float getNum() {return 3.0f;} 3. } 4. 5. public class Sub extends Super { 6. 7. } Which method, placed at line 6, will cause a compiler error?()
第16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17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18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19题:
doX();
X.doX();
x.X.doX();
x.X myX = new x.X(); myX.doX();
第20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21题:
0
1
2
3
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:
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24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.