public class Employee{ private String name; public Employee(String name){ this.name = name; } public String getName(){ return name; } } public class Manager extends Employee{ private String department; public Manager(String name,String department){ this.department = department; super(name); (应于上一行掉位置) System.out.println(getName()); } } Super的位置是否在方法的首行 执行语句new Manager(“smith”,”SALES”)后程序的输出是哪项?()A、 smithB、 nullC、 SALESD、 编译错误
public class Employee{ private String name; public Employee(String name){ this.name = name; } public String getName(){ return name; } } public class Manager extends Employee{ private String department; public Manager(String name,String department){ this.department = department; super(name); (应于上一行掉位置) System.out.println(getName()); } } Super的位置是否在方法的首行 执行语句new Manager(“smith”,”SALES”)后程序的输出是哪项?()
- A、 smith
- B、 null
- C、 SALES
- D、 编译错误
相关考题:
为使下列代码正常运行,应该在下划线处填入的选项是abstract class Person{public Person(String n)!name=n;}public____String getDescription();public String getName(){return name;}private String name;}A.staticB.privateC.abstractD.final
阅读下列代码段 abstract class Person{ public Person(String n){ name=n; } public______String getDescription(); public String getName(){ } private String name; } 在下画线处应填入的修饰符是A.staticB.abstractC.protectedD.final
阅读下面代码 abstract class Person { public Person(String n) { name=n; } public______String getDescription(); public String getName() { return name; } private String name; } 在下画线处应填入的修饰符是A.staticB.abstractC.protectedD.final
interface Playable {void play();}interface Bounceable {void play();}interface Rollable extends Playable, Bounceable {Ball ball = new Ball("PingPang");}class Ball implements Rollable {private String name;public String getName() {return name;}public Ball(String name) {this.name = name;}public void play() {ball = new Ball("Football");System.out.println(ball.getName());}}这个错误不容易发现。
为使下列代码正常运行,应该在下画线处填入的选项是( )。 abstract class person{ public Person(String n){ name=n: } Public String getDescription; public String getName{ return name; } private string name; }A.staticB.privateC.abstractD.final
阅读以下说明和Java代码,将应填入(n)处的字句写在对应栏内。[说明]在一些大型系统中,大多数的功能在初始化时要花费很多时间,如果在启动的时候,所有功能(连不用的功能)都要全面初始化的话,会连带影响到应用软件要花很多时间才能启动。因此常将程序设计成到了实际要使用某种功能的阶段才初始化该功能。以下示例展示了Proxy(代理)模式,PrinterProxy类执行一些比较“轻”的方法——设置名称和取得名称,需要真正执行“重”的方法——真正打印——时才初始Print类。图6-1显示了各个类间的关系。[图6-1][Java代码]//Printable.JavapubliC (1) Printable{public abstract void setPrinterName(String name);public abstract String getprinterName();public abstract void print(String string);}//Printer.Javapublic class Printer implements Printable{private String name;public Printer(){System.out.println("正在产生Printer的对象实例");}public Printer(String name){this.name=name;heavyJob("正在产生Printer的对象实例("+name+")");public void setPrinterName(String name){this.name=name;public String getPrinterName(){return name;public void print(String string){System.out.println("===" +name+" ====");System.out.println(string);}}//PrinterProxy.Javapublic class PrinterProxy (2) Printable{private String name;private Printer real;public PrinterProxy(){}public PrinterProxy(String name){this.name=name;}public gynchronized void setPrinterName(String name){if( (3) ){real.setPrinterName(name);}this.name=name;}public String getprinterName(){return name;}public void print(String string){(4);real.print(string);}private synchronized void realize(){//产生真正的Printer对象if(real==null){real=(5);}}}(1)
执行以下代码后,下面哪些描述是正确的() public class Student{ private String name = “Jema”; public void setName(String name){ this.name = name; } public String getName(){ return this.name; } public static void main(String[] args){ Student s; System.out.println(s.getName()); } }A、输出nullB、第10行编译报错C、第11行编译报错D、输出Jema
public class Pet{ private String name; public Pet(){ System.out.print(1); } public Pet(String name){ System.out.print(2); } } public class Dog extends Pet{ public Dog(String name){ System.out.print(3); } } 执行new Dog(“棕熊”);后程序输出是哪项?() A、 23B、 13C、 123D、 321
1. public class Employee { 2. String name; 3. double baseSalary; 4. Employee(String name, double baseSalary) { 5. this.name = name; 6. this.baseSalary = baseSalary; 7. } 8. } And: 1. public class Salesperson extends Employee { 2. double commission; 3. public Salesperson(String name, double baseSalary, 4. double commission) { 5. // insert code here 6. } 7. } Which code, inserted at line 7, completes the Salesperson constructor?() A、 this.commission = commission;B、 superb(); commission = commission;C、 this.commission = commission; superb();D、 super(name, baseSalary); this.commission = commission;E、 super(); this.commission = commission;F、 this.commission = commission; super(name, baseSalary);
public class Pet{ private String name; public Pet(String name){ this.name = name; } public void speak(){ System.out.print(name); } } public class Dog extends Pet{ public Dog(String name){ super(name); } public void speak(){ super.speak(); System.out.print(“ Dog ”); } } 执行代码 Pet pet = new Dog(“京巴”); pet.speak(); 后输出的内容是哪项?() A、 京巴B、 京巴 DogC、 nullD、 Dog京巴
public class Employee{ private String name; public Employee(String name){ this.name = name; } public void display(){ System.out.print(name); } } public class Manager extends Employee{ private String department; public Manager(String name,String department){ super(name); this.department = department; } public void display(){ System.out.println(super.display()+”,”+department); } } 执行语句new Manager(“smith”,”SALES”)后程序的输出是哪项?() A、 smith,SALESB、 null,SALESC、 smith,nullD、 null,nullE、 编译错误
public class Pet{ private String name; public Pet(){ System.out.print(1); } public Pet(String name){ System.out.print(2); } } public class Dog extends Pet{ public Dog(){ System.out.print(4); } public Dog(String name){ super(name); System.out.print(3); } } 执行new Dog(“棕熊”);后程序输出是哪项?() A、 33B、 13C、 23D、 123
public class Employee{ private String name; public Employee(String name){ this.name = name; } public String getName(){ return name; } } public class Manager extends Employee{ private String department; public Manager(String name,String department){ this.department = department; super(name); System.out.println(getName()); } } 执行语句new Manager(“smith”,”SALES”)后程序的输出是哪项?() A、 smithB、 nullC、 SALESD、 编译错误
public class Employee{ private String name; public Employee(String name){ this.name = name; } public void display(){ System.out.print(name); } } public class Manager extends Employee{ private String department; public Manager(String name,String department){ super(name); this.department = department; } public void display(){ System.out.println( super.display()+”,”+department); } } 执行语句new Manager(“smith”,”SALES”)后程序的输出是哪项?() A、 smith,SALESB、 null,SALESC、 smith,nullD、 null,null
public class Plant { private String name; public Plant(String name) { this.name = name; } public String getName() { return name; } } public class Tree extends Plant { public void growFruit() { } public void dropLeaves() { } } Which is true?() A、 The code will compile without changes.B、 The code will compile if public Tree() { Plant(); } is added to the Tree class.C、 The code will compile if public Plant() { Tree(); } is added to the Plant class.D、 The code will compile if public Plant() { this(”fern”); } is added to the Plant class.E、 The code will compile if public Plant() { Plant(”fern”); } is added to the Plant class.
Given the following code: 1) class Parent { 2) private String name; 3) public Parent(){} 4) } 5) public class Child extends Parent { 6) private String department; 7) public Child() {} 8) public String getValue(){ return name; } 9) public static void main(String arg[]) { 10) Parent p = new Parent(); 11) } 12) } Which line will cause error?() A、 line 3B、 line 6C、 line 7D、 line 8E、 line 10
11. class Person { 12. String name = “No name‟; 13. public Person(String nm) { name = nm; } 14. } 15. 16. class Employee extends Person { 17. String emplD = “0000”; 18. public Employee(String id) { empID = id; } 19. } 20. 21. public class EmployeeTest { 22. public static void main(String[] args) { 23. Employee e = new Employee(”4321”); 24. System.out.println(e.empID); 25. } 26. } What is the result?() A、 4321B、 0000C、 An exception is thrown at runtime.D、 Compilation fails because of an error in line 18.
public class Pet{ private String name; public Pet(){ System.out.print(1); } public Pet(String name){ System.out.print(2); } } public class Dog extends Pet{ public Dog(){ System.out.print(4); } public Dog(String name){ this(); System.out.print(3); } } 执行new Dog(“棕熊”);后程序输出是哪项?() A、 143B、 423C、 243D、 1134
public class Employee{ private String name; public Employee(String name){ this.name = name; } public String getName(){ return name; } } public class Manager extends Employee{ public Manager(String name){ System.out.println(getName()); } } 执行语句new Manager(“smith”)后程序的输出是哪项?() A、 smithB、 nullC、 编译错误D、 name
public class NamedCounter { private final String name; private int count; public NamedCounter(String name) { this.name = name; } public String getName() { return name; } public void increment() { coount++; } public int getCount() { return count; } public void reset() { count = 0; } } Which three changes should be made to adapt this class to be used safely by multiple threads? ()A、 declare reset() using the synchronized keywordB、 declare getName() using the synchronized keywordC、 declare getCount() using the synchronized keywordD、 declare the constructor using the synchronized keywordE、 declare increment() using the synchronized keyword
单选题public class Pet{ private String name; public Pet(){ System.out.print(1); } public Pet(String name){ System.out.print(2); } } public class Dog extends Pet{ public Dog(String name){ System.out.print(3); } } 执行new Dog(“棕熊”);后程序输出是哪项?()A 23B 13C 123D 321
单选题public class Employee{ private String name; public Employee(String name){ this.name = name; } public void display(){ System.out.print(name); } } public class Manager extends Employee{ private String department; public Manager(String name,String department){ super(name); this.department = department; } public void display(){ System.out.println(super.display()+”,”+department); } } 执行语句new Manager(“smith”,”SALES”)后程序的输出是哪项?()A smith,SALESB null,SALESC smith,nullD null,nullE 编译错误
单选题public class Plant { private String name; public Plant(String name) { this.name = name; } public String getName() { return name; } } public class Tree extends Plant { public void growFruit() { } public void dropLeaves() { } } Which is true?()A The code will compile without changes.B The code will compile if public Tree() { Plant(); } is added to the Tree class.C The code will compile if public Plant() { Tree(); } is added to the Plant class.D The code will compile if public Plant() { this(”fern”); } is added to the Plant class.E The code will compile if public Plant() { Plant(”fern”); } is added to the Plant class.
单选题public class Employee{ private String name; public Employee(String name){ this.name = name; } public String getName(){ return name; } } public class Manager extends Employee{ public Manager(String name){ System.out.println(getName()); } } 执行语句new Manager(“smith”)后程序的输出是哪项?()A smithB nullC 编译错误D name
单选题Given the following code: 1) class Parent { 2) private String name; 3) public Parent(){} 4) } 5) public class Child extends Parent { 6) private String department; 7) public Child() {} 8) public String getValue(){ return name; } 9) public static void main(String arg[]) { 10) Parent p = new Parent(); 11) } 12) } Which line will cause error?()A line 3B line 6C line 7D line 8E line 10
单选题public class Pet{ private String name; public Pet(String name){ this.name = name; } public void speak(){ System.out.print(name); } } public class Dog extends Pet{ public Dog(String name){ super(name); } public void speak(){ super.speak(); System.out.print(“ Dog ”); } } 执行代码 Pet pet = new Dog(“京巴”); pet.speak(); 后输出的内容是哪项?()A 京巴B 京巴 DogC nullD Dog京巴
单选题执行以下代码后,下面哪些描述是正确的() public class Student{ private String name = “Jema”; public void setName(String name){ this.name = name; } public String getName(){ return this.name; } public static void main(String[] args){ Student s; System.out.println(s.getName()); } }A输出nullB第10行编译报错C第11行编译报错D输出Jema