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我感覺(jué)寫(xiě)成帶參數(shù)的會(huì)比較實(shí)用,但這里能否寫(xiě)成帶參數(shù)的呢,如果可以,要在父類(lèi)中就寫(xiě)嗎,要怎么實(shí)現(xiàn)抽象?

//這是無(wú)參的
package?com.LEE;
?
public?abstract?class?Shape?{
public?abstract?void?perimeter();
public?abstract?void?area();
}
//************************************************
package?com.LEE;
?
public?class?Rectangle?extends?Shape?{
int?a=1,b=2;
@Override
public?void?perimeter()?{
//?TODO?Auto-generated?method?stub
System.out.println("矩形周長(zhǎng)為"+2*(a+b));
}
?
@Override
public?void?area()?{
//?TODO?Auto-generated?method?stub
System.out.println("矩形面積為"+a*b);
}
?
}
//*************************************************
package?com.LEE;
?
public?class?Circle?extends?Shape?{
int?r=2;
@Override
public?void?perimeter()?{
//?TODO?Auto-generated?method?stub
System.out.println("圓形周長(zhǎng)是"+(2*3.14*r));
}
?
@Override
public?void?area()?{
//?TODO?Auto-generated?method?stub
System.out.println("圓形面積是"+(3.14*r*r));
}
?
}
//****************************************************
package?com.LEE;
?
public?class?Initial?{
public?static?void?main(String[]?args){
Shape?Rec=new?Rectangle();
Shape?Cir=new?Circle();
Rec.perimeter();
Rec.area();
Cir.perimeter();
Cir.area();
}

}


正在回答

3 回答

package com.imooc;

public abstract class Shape {
?public abstract void area(double r);
?public abstract void area(double a,double b);
?public abstract void perimeter(double r);
?public abstract void perimeter(double a,double b);
}

package com.imooc;

public class Circle extends Shape {

?@Override
?public void area(double r) {
??// TODO Auto-generated method stub
??System.out.println("圓的面積是:"+3.14*3.14*r);

?}

?@Override
?public void area(double a, double b) {
??// TODO Auto-generated method stub

?}

?@Override
?public void perimeter(double r) {
??// TODO Auto-generated method stub
??System.out.println("圓的周長(zhǎng)是:"+2*3.14*r);
?}

?@Override
?public void perimeter(double a, double b) {
??// TODO Auto-generated method stub

?}

}

package com.imooc;

public class Rectangle extends Shape {

?@Override
?public void area(double r) {
??// TODO Auto-generated method stub

?}

?@Override
?public void area(double a, double b) {
??// TODO Auto-generated method stub
??System.out.println("矩形的面積是:"+a*b);
?}

?@Override
?public void perimeter(double r) {
??// TODO Auto-generated method stub

?}

?@Override
?public void perimeter(double a, double b) {
??// TODO Auto-generated method stub
??System.out.println("矩形的周長(zhǎng)是:"+2*(a+b));
?}

}

package com.imooc;

public class Initial {

?/**
? * @param args
? */
?public static void main(String[] args) {
??// TODO Auto-generated method stub
??Shape cir=new Circle();
??Shape rec=new Rectangle();
??cir.area(3.0);
??cir.perimeter(3.0);
??rec.area(2, 3);
??rec.perimeter(2, 3);
?}

}

0 回復(fù) 有任何疑惑可以回復(fù)我~

能文不武寫(xiě)的是錯(cuò)的

0 回復(fù) 有任何疑惑可以回復(fù)我~
//父類(lèi)抽象方法和子類(lèi)方法實(shí)現(xiàn),唯一的區(qū)別就是,父類(lèi)抽象方法中{}是空的,哈哈O(∩_∩)O哈哈~
package?com.LEE;
??
public?abstract?class?Shape?{????????//在父類(lèi)方法中,所帶的參數(shù)都是在()里面聲明的
public?abstract?void?perimeter(int?a,int?b);?
public?abstract?void?area(int?r);?
}
//************************************************
package?com.LEE;
??
public?class?Rectangle?extends?Shape?{
//int?a=1,b=2;
//同樣,因?yàn)槟氵@個(gè)方法已經(jīng)是帶參數(shù)的了,所以在方法里面就不需要定義變量的值了這個(gè)步驟應(yīng)該放到main方法里面去做
@Override
public?void?perimeter(int?a,?int?b)?{
//?TODO?Auto-generated?method?stub
System.out.println("矩形周長(zhǎng)為"+2*(a+b));
}
??
@Override
public?void?area(int?a,?int?b)?{
//?TODO?Auto-generated?method?stub
System.out.println("矩形面積為"+a*b);
}
??
}
//*************************************************
package?com.LEE;
??
public?class?Circle?extends?Shape?{
//int?r=2;
@Override
public?void?perimeter(int?r)?{
//?TODO?Auto-generated?method?stub
System.out.println("圓形周長(zhǎng)是"+(2*3.14*r));
}
??
@Override
public?void?area(int?r)?{
//?TODO?Auto-generated?method?stub
System.out.println("圓形面積是"+(3.14*r*r));
}
??
}
//****************************************************
package?com.LEE;
??
public?class?Initial?{
public?static?void?main(String[]?args){
Shape?Rec=new?Rectangle();
Shape?Cir=new?Circle();
//我們可以在這里定義具體參數(shù)的值
int?a=1,b=2
Rec.perimeter(a,b);
Rec.area(a,b);
int?r=2
Cir.perimeter(r);
Cir.area(r);
}
?
}


0 回復(fù) 有任何疑惑可以回復(fù)我~
#1

MoreClass

父類(lèi)里面abstract void perimeter(int a, int b); 那么在兩個(gè)子類(lèi)里面,無(wú)論是長(zhǎng)方形還是圓形所得到的獲得變長(zhǎng)的方法也都是需要ab兩個(gè)參數(shù)吧。同理計(jì)算面積也是。
2015-03-30 回復(fù) 有任何疑惑可以回復(fù)我~
#2

XFE_星城前端_Peter 回復(fù) MoreClass

是的,樓下有人指出我的代碼有問(wèn)題,如果有時(shí)間的話,可以幫我驗(yàn)證下!太粗心了我!
2015-06-06 回復(fù) 有任何疑惑可以回復(fù)我~

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我感覺(jué)寫(xiě)成帶參數(shù)的會(huì)比較實(shí)用,但這里能否寫(xiě)成帶參數(shù)的呢,如果可以,要在父類(lèi)中就寫(xiě)嗎,要怎么實(shí)現(xiàn)抽象?

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