corejava-day04-面试笔试题

C.Beagle b4 = dog2;
D.None of the above statements will compile
练习14
Given the following:
class X{ void do(){} }
class Y extends X{ void do2(){} }
class Chrome {
F.It is unlikely that changes made to one class will require any changes in another.
练习9
Given:
class Plant {
String getName(){
return "plant";
}
Plant getType(){
D.Woop has-a Hmpf and Woop is-a Zing.
E.Zing has-a Hmpf and Zing is-a Woop.
练习11
Given:
class Programmer {
Programmer debug(){
return this;
}
}
class SCJP extends Programmer{
}
}
class Tulip extends Flower{ }
Which statement(s),inserted at line x,will compile?(Choose all that apply.)
A.Flower getType(){
return this;
}
B.String getType(){
乐器类（Instrument）,是所有乐器的父类，有一个演奏的方法play,参数是Note类型
风管乐器（Wind），是Instrument的子类
弦乐器(Stringed)，是Instrument的子类
扩展其他的类型
写Music类，有一个演奏的方法tune,接收Instrument的类型，创建几个种乐器对象，然后演奏出来
写一个程序，把若干各种类型的员工放在一个Employee数组里，写一个函数，打印出某月每个员工的工资数额。注意：要求把每个类都做成完全封装，不允许非私有化属性。
练习5、Which statement(s) are true?(Choose all that apply.)
A. Has-a relationships always rely on inheritance.
A.The attributes of the class are all private .
B.The class refers to a small number of other objects.
C.The object contains only a small number of variables.
public Top (String s) { System.out.print("B"); }
}
public class Bottom2 extends Top {
public Bottom2(String s) { System.out.print("D"); }
public static void main( String[] args ){
return "this";
}
C.Plant getType(){
return this;
}
D.Tulip getType(){
return new Tulip();
}
练习10
Given:
class Zing {
protected Hmpf h;
}
class Woop extends Zing{ }
练习4
某公司的雇员分为以下若干类：
Employee：这是所有员工总的父类，属性：员工的姓名，员工的生日月份。方法：getSalary(int month)根据参数月份来确定工资，如果该月员工过生日，则公司会额外奖励100元。
SalariedEmployee：Employee的子类，拿固定工资的员工。属性：月薪
Uber(int x){
this();
y = y*2;
}
Uber(){
y++;
}
}
class Minor extends Uber {
Minor(){
super(y);
y = y + 3;
}
public static void main(String[] args) {
new Minor();
System.out.println(y);
// line x: insert code here
}
Which, inserted at line x, will compile?(Choose all that apply.)
A.Programmer debug(){
return this;} NhomakorabeaB.SCJP debug(){
return this;
}
C.Object debug(){
return this;
}
D.int debug(){
return 1;
}
E.int debug(int x){
return 1;
}
F.Object debug(int x){
return this;
}
练习12
Given:
class Uber{
static int y = 2;
练习1
使用extends写出下列类的继承体系代码
练习2练习多态
创建一个AutoCAD画图软件，各创建3个Circle和2个Rect，用一个数组保存，遍历数组，将每种形状画出来
Shape（形状）
draw()
Circle(圆形)
draw()
Rect(矩形)
draw()
练习3练习多态
音符类(Note)，里面有一些常量，比如Do、Le
HourlyEmployee：Employee的子类，按小时拿工资的员工，每月工作超出160小时的部分按照1.5倍工资发放。属性：每小时的工资、每月工作的小时数
SalesEmployee：Employee的子类，销售人员，工资由月销售额和提成率决定。属性：月销售额、提成率
BasePlusSalesEmployee：SalesEmployee的子类，有固定底薪的销售人员，工资由底薪加上销售提成部分。属性：底薪。
E. Has-a relationships are always tightly couped.
练习6、Given：
class Cliders {
public final void flipper () {
System.out.println("Flip a Clidder");
}
}
public class Clidlets extends Cliders {
new Bottom2("C");
System.out.println(" ");
}
}
What is the result?
A.BD
B.DB
C.BDC
D.DBC
pilation fails.
练习8
Select the two statements that best indicate a situation with low coupling.(Choose two.)
return this;
}
}
class Flower extends Plant{
// line x: insert code here
public static void main(String[] args){
Flower f = new Flower();
System.out.println(f.getType());
class Hmpf {}
Which is true?(Choose all that apply.)
A.Woop is-a Hmpf and has-a Hmpf.
B.Zing is-a Woop and has-a Hmpf.
C.Hmpf has-a Woop and Woop is-a Zing.
Dog dog2 = bl;
// line x :insert code here
}
}
Which, inserted at line x, will compile?(Choose all that apply.)
A.Beagle b2 = (Beagle) dog1;
B.Beagle b3 = (Beagle) dog2;
public void flipper () {
Sysetm.out.println("Flip a Clidlet.");
super.flipper ();
}
public static void main (String [] args) {
new Cliders().flipper();
}
}
What is the result?
D.The object is referred to using an anonymous variable, not directly.
E.The reference variable is declared for an interface type, not a class. The interface provides a small number of methods.