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?()
第1题:
public class Person { private String name, comment; private int age; public Person(String n, int a, String c) { name = n; age = a; comment = c; } public boolean equals(Object o) { if(! (o instanceof Person)) return false; Person p = (Person)o; return age == p.age && name.equals(p.name); } } What is the appropriate definition of the hashCode method in class Person?()
第2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?()
第3题:
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.static
B.abstract
C.protected
D.final
第4题:
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?()
第5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?()
第6题:
class Parent { String one, two; public Parent(String a, String b){ one = a; two = b; } public void print(){ System.out.println(one); } } public class Child extends Parent { public Child(String a, String b){ super(a,b); } public void print(){ System.out.println(one + " to " + two); } public static void main(String arg[]){ Parent p = new Parent("south", "north"); Parent t = new Child("east", "west"); p.print(); t.print(); } } Which of the following is correct?()
第7题:
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?()
第8题:
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.static
B.private
C.abstract
D.final
第9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(){ 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?()
第10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?()