ClassOne.java 1. package com.abc.pkg1; 2. public class ClassOne { 3. private char var = ‘a’; 4. char getVar() {return var;} 5. } ClassTest.java 1. package com.abc.pkg2; 2. import com.abc.pkg1.ClassOne; 3. public class ClassTest extends ClassOne { 4. public static void main(String[]args) { 5. char a = new ClassOne().getVar(); 6. char b = new ClassTest().getVar(); 7. } 8. } What is the result?() A、 Compilation will fail.B、 Compilation succeeds and no exceptions are thrown.C、 Compilation succeeds but an exception is thrown at line 5 in ClassTest.java.D、 Compilation succeeds but an exception is thrown at line 6 in ClassTest.java.
ClassOne.java 1. package com.abc.pkg1; 2. public class ClassOne { 3. private char var = ‘a’; 4. char getVar() {return var;} 5. } ClassTest.java 1. package com.abc.pkg2; 2. import com.abc.pkg1.ClassOne; 3. public class ClassTest extends ClassOne { 4. public static void main(String[]args) { 5. char a = new ClassOne().getVar(); 6. char b = new ClassTest().getVar(); 7. } 8. } What is the result?()
- A、 Compilation will fail.
- B、 Compilation succeeds and no exceptions are thrown.
- C、 Compilation succeeds but an exception is thrown at line 5 in ClassTest.java.
- D、 Compilation succeeds but an exception is thrown at line 6 in ClassTest.java.
相关考题:
1. class BaseClass { 2. private float x = 1.of; 3. protected float getVar() { return x; } 4. } 5. class SubClass extends BaseClass { 6. private float x = 2.Of; 7. // insert code here 8. } Which two are valid examples of method overriding when inserted at line 7?() A、 float getVar() { return x; }B、 public float getVar() { return x; }C、 public double getVar() { return x; }D、 protected float getVar() { return x; }E、 public float getVar(float f) { return f; }
1. class Super { 2. public float getNum() { return 3.0f; } 3. } 4. 5. public class Sub extends Super { 6. 7. } Which method, placed at line6, causes compilation to fail?() A、 public void getNum(){}B、 public void getNum(double d){}C、 public float getNum() { return 4.0f; }D、 public double getNum(float d) { return 4.0d; }
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?() A、 Line 4 of class Target can be changed to return i++;B、 Line 2 of class Target can be changed to private int i = 1;C、 Line 3 of class Target can be changed to private int addOne() {D、 Line 2 of class Target can be changed to private Integer i = 0;
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?() A、 Compilation will succeed for all classes and interfaces.B、 Compilation of class C will fail because of an error in line 2.C、 Compilation of class C will fail because of an error in line 6.D、 Compilation of class AImpl will fail because of an error in line 2.
1. public class a { 2. public void method1() { 3. try { 4. B b=new b(); 5. b.method2(); 6. // more code here 7. } catch (TestException te) { 8. throw new RuntimeException(te); 9. } 10. } 11. } 1. public class b { 2. public void method2() throws TestException { 3. // more code here 4. } 5. } 1. public class TestException extends Exception { 2. } Given: 31. public void method() { 32. A a=new a(); 33. a.method1(); 34. } Which is true if a TestException is thrown on line 3 of class b?()A、 Line 33 must be called within a try block.B、 The exception thrown by method1 in class a is not required to be caught.C、 The method declared on line 31 must be declared to throw a RuntimeException.D、 On line 5 of class a, the call to method2 of class b does not need to be placed in a try/catch block.
Given a file GrizzlyBear.java: 1. package animals.mammals; 2. 3. public class GrizzlyBear extends Bear { 4. void hunt() { 5. Salmon s = findSalmon(); 6. s.consume(); 7. } 8. } and another file, Salmon.java: 1. package animals.fish; 2. 3. public class Salmon extends Fish { 4. void consume() { /* do stuff */ } 5. } Assume both classes are defined in the correct directories for theft packages, and that the Mammal class correctly defines the findSalmon() method. Which two changes allow this code to compile correctly?()A、 add public to the start of line 4 in Salmon.javaB、 add public to the start of line 4 in GrizzlyBear.javaC、 add import animals.mammals.*; at line 2 in Salmon.javaD、 add import animals.fish.*; at line 2 in GrizzlyBear.javaE、 add import animals.fish.Salmon.*; at line 2 in GrizzlyBear.javaF、 add import animals.mammals.GrizzlyBear.*;at line 2 in Salmon.java
1. abstract class AbstractIt { 2. abstract float getFloat(); 3. } 4. public class AbstractTest extends AbstractIt { 5. private float f1 = 1.0f; 6. private float getFloat() { return f1; } 7. } What is the result?() A、 Compilation succeeds.B、 An exception is thrown.C、 Compilation fails because of an error at line 2.D、 Compilation fails because of an error at line 6.
Given: 1. public class Method Over { 2. public void set Var (int a, int b, float c) { 3. } 4. } Which two overload the set Var method()?A、 private void set Var(int a, float c, int b) {}B、 protected void set Var(int a, int b, float c) {}C、 public int set Var(int a, float c, int b) {return a:}D、 public int set Var(int a, int b, float c) {return a:}E、 protected float set Var(int a, int b, float c) {return c:}
1. class SuperClass { 2. public a geta() { 3. return new a(); 4. } 5. } 6. class SubClass extends SuperClass { 7. public b geta() { 8. return new b(); 9. } 10. } Which is true?() A、 Compilation will succeed if a extends b.B、 Compilation will succeed if b extends a.C、 Compilation will always fail because of an error in line 7.D、 Compilation will always fail because of an error in line 8.
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”? ()A、doX();B、X.doX();C、x.X.doX();D、x.X myX = new x.X(); myX.doX();
现有: 1. class Synapse { 2. protected int gap() { return 7; } 3. } 4. 5. class Creb extends Synapse { 6. // insert code here 7. } 分别插入到第 6 行,哪三行可以编译?()A、 int gap() { return 7; }B、 public int gap() { return 7; }C、 private int gap(int x) { return 7; }D、 protected Creb gap() { return this; }E、 public int gap() { return Integer.getInteger ("42"); }
ClassOne.java: 1. package com.abe.pkg1; 2. public class ClassOne { 3. private char var = ‘a’; 4. char getVar() { return var; } 5. } ClassTest.java: 1. package com.abe.pkg2; 2. import com.abc.pkg1.ClassOne; 3. public class ClassTest extends ClassOne { 4. public static void main(String[] args) { 5. char a = new ClassOne().getVar();6. char b = new ClassTest().getVar(); 7. } 8. } What is the result?()A、 Compilation fails.B、 Compilation succeeds and no exceptions are thrown.C、 An exception is thrown at line 5 in ClassTest.java.D、 An exception is thrown at line 6 in ClassTest.java.
1. public class OuterClass { 2. private double d1 = 1.0; 3. // insert code here 4. } Which two are valid if inserted at line 3?() A、 static class InnerOne { public double methoda() { return d1; } }B、 static class InnerOne { static double methoda() { return d1; } }C、 private class InnerOne { public double methoda() { return d1; } }D、 protected class InnerOne { static double methoda() { return d1; } }E、 public abstract class InnerOne { public abstract double methoda(); }
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?() A、 Public float getNum() {return 4.0f; }B、 Public void getNum () { }C、 Public void getNum (double d) { }D、 Public double getNum (float d) {retrun 4.0f; }
ClassOne.java package com.abc.pkg1; public class ClassOne { private char var = ‘a‘; char getVar() {return var;} } ClassTest.java package com.abc.pkg2; import com.abc.pkg1.ClassOne; public class ClassTest extends ClassOne { public static void main(Stringargs) { char a = new ClassOne().getVar(); char b = new ClassTest().getVar(); } } What is the result?() A、 Compilation will fail.B、 Compilation succeeds and no exceptions are thrown.C、 Compilation succeeds but an exception is thrown at line 5 in ClassTest.java.D、 Compilation succeeds but an exception is thrown at line 6 in ClassTest.java.
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?() A、 process(bytes);B、 BitUtils.process(bytes);C、 app.BitUtils.process(bytes);D、 util.BitUtils.process(bytes);E、 import util.BitUtils. *; process(bytes);F、 SomeApp cannot use the process method in BitUtils.
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?() A、 process(bytes);B、 BitUtils.process(bytes);C、 util.BitUtils.process(bytes);D、 SomeApp cannot use methods in BitUtils.E、 import util.BitUtils.*; process(bytes);
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”?() A、 import utils.*;B、 static import utils.*;C、 import utils.Repetition.*;D、 static import utils.Repetition. *;E、 import utils.Repetition.twice();F、 import static utils.Repetition.twice;G、 static import utils.Repetition.twice;
1. public class Blip { 2. protected int blipvert(int x) { return 0; } 3. } 4. class Vert extends Blip { 5. // insert code here 6. } Which five methods, inserted independently at line 5, will compile?() A、 public int blipvert(int x) { return 0; }B、 private int blipvert(int x) { return 0; }C、 private int blipvert(long x) { return 0; }D、 protected long blipvert(int x, int y) { return 0; }E、 protected int blipvert(long x) { return 0; }F、 protected long blipvert(long x) { return 0; }G、protected long blipvert(int x) { return 0; }
单选题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?()A process(bytes);B BitUtils.process(bytes);C app.BitUtils.process(bytes);D util.BitUtils.process(bytes);E import util.BitUtils. *; process(bytes);F SomeApp cannot use the process method in BitUtils.
单选题1. class SuperClass { 2. public a geta() { 3. return new a(); 4. } 5. } 6. class SubClass extends SuperClass { 7. public b geta() { 8. return new b(); 9. } 10. } Which is true?()A Compilation will succeed if a extends b.B Compilation will succeed if b extends a.C Compilation will always fail because of an error in line 7.D Compilation will always fail because of an error in line 8.
单选题1. class Super { 2. public float getNum() { return 3.0f; } 3. } 4. 5. public class Sub extends Super { 6. 7. } Which method, placed at line6, causes compilation to fail?()A public void getNum(){}B public void getNum(double d){}C public float getNum() { return 4.0f; }D public double getNum(float d) { return 4.0d; }
多选题1. class BaseClass { 2. private float x = 1.of; 3. protected float getVar() { return x; } 4. } 5. class SubClass extends BaseClass { 6. private float x = 2.Of; 7. // insert code here 8. } Which two are valid examples of method overriding when inserted at line 7?()Afloat getVar() { return x; }Bpublic float getVar() { return x; }Cpublic double getVar() { return x; }Dprotected float getVar() { return x; }Epublic float getVar(float f) { return f; }
多选题1. public class OuterClass { 2. private double d1 = 1.0; 3. // insert code here 4. } Which two are valid if inserted at line 3?()Astatic class InnerOne { public double methoda() { return d1; } }Bstatic class InnerOne { static double methoda() { return d1; } }Cprivate class InnerOne { public double methoda() { return d1; } }Dprotected class InnerOne { static double methoda() { return d1; } }Epublic abstract class InnerOne { public abstract double methoda(); }
单选题ClassOne.java package com.abc.pkg1; public class ClassOne { private char var = ‘a‘; char getVar() {return var;} } ClassTest.java package com.abc.pkg2; import com.abc.pkg1.ClassOne; public class ClassTest extends ClassOne { public static void main(Stringargs) { char a = new ClassOne().getVar(); char b = new ClassTest().getVar(); } } What is the result?()A Compilation will fail.B Compilation succeeds and no exceptions are thrown.C Compilation succeeds but an exception is thrown at line 5 in ClassTest.java.D Compilation succeeds but an exception is thrown at line 6 in ClassTest.java.
多选题Given: 1. public class Method Over { 2. public void set Var (int a, int b, float c) { 3. } 4. } Which two overload the set Var method()?Aprivate void set Var(int a, float c, int b) {}Bprotected void set Var(int a, int b, float c) {}Cpublic int set Var(int a, float c, int b) {return a:}Dpublic int set Var(int a, int b, float c) {return a:}Eprotected float set Var(int a, int b, float c) {return c:}
单选题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?()A Public float getNum() {return 4.0f; }B Public void getNum () { }C Public void getNum (double d) { }D Public double getNum (float d) {retrun 4.0f; }