Compilation will fail.
Compilation succeeds and no exceptions are thrown.
Compilation succeeds but an exception is thrown at line 5 in ClassTest.java.
Compilation succeeds but an exception is thrown at line 6 in ClassTest.java.
第1题:
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?()
第2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?()
第3题:
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?()
第4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?()
第5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?()
第6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7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8题:
process(bytes);
BitUtils.process(bytes);
app.BitUtils.process(bytes);
util.BitUtils.process(bytes);
import util.BitUtils. *; process(bytes);
SomeApp cannot use the process method in BitUtils.
第9题:
public void getNum(){}
public void getNum(double d){}
public float getNum() { return 4.0f; }
public double getNum(float d) { return 4.0d; }
第10题:
Compilation will fail.
Compilation succeeds and no exceptions are thrown.
Compilation succeeds but an exception is thrown at line 5 in ClassTest.java.
Compilation succeeds but an exception is thrown at line 6 in ClassTest.java.
第11题:
process(bytes);
BitUtils.process(bytes);
util.BitUtils.process(bytes);
SomeApp cannot use methods in BitUtils.
import util.BitUtils.*; process(bytes);
第12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13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()?
第14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15题:
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?()
第16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17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18题:
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?()
第19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20题:
Compilation will fail.
Compilation succeeds and no exceptions are thrown.
Compilation succeeds but an exception is thrown at line 5 in ClassTest.java.
Compilation succeeds but an exception is thrown at line 6 in ClassTest.java.
第21题:
float getVar() { return x; }
public float getVar() { return x; }
public double getVar() { return x; }
protected float getVar() { return x; }
public float getVar(float f) { return f; }
第22题:
Compilation fails.
Compilation succeeds and no exceptions are thrown.
An exception is thrown at line 5 in ClassTest.java.
An exception is thrown at line 6 in ClassTest.java.
第23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24题:
Public float getNum() {return 4.0f; }
Public void getNum () { }
Public void getNum (double d) { }
Public double getNum (float d) {retrun 4.0f; }