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  mqlobpgvdm 2012-01-12 00:00:00

  樓主，你應(yīng)該是培訓(xùn)生吧！自己先敲懂嗎？

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  zcl711028love 2012-01-08 00:00:00

  LZ還是不要干程序了··這種不是問題的問題還需要?jiǎng)e人提供現(xiàn)成的答案么？自己好好看看書··對(duì)基礎(chǔ)知識(shí)了解更深一點(diǎn)會(huì)更好··

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  陸超陸超陸超 2012-01-06 00:00:00

  abstract class Shape { public abstract double m1(); // 用來(lái)計(jì)算圖形的周長(zhǎng) public abstract double m2(); // 用來(lái)計(jì)算圖形的面積 } class Rect extends Shape { double x; private double y; public Rect(double x， double y) { this.x = x; this.y = y; } public double m1() { return 2 * (x + y); } public double m2() { return x * y; } } class Squ extends Shape { private double x; public Squ(double x) { this.x = x; } public double m1() { return 4 * x; } public double m2() { return Math.pow(x， 2); } } class Circle extends Shape { private double r; public Circle(double r) { this.r = r; } public double m1() { return 2 * r * Math.PI; } public double m2() { return Math.pow(r， 2) * Math.PI; } } public class ShapeExc { public static void print(Shape shape) { StringBuffer sb = new StringBuffer(); if(shape instanceof Rect){ sb.append("長(zhǎng)方形周長(zhǎng)："+shape.m1()+"\n"+"長(zhǎng)方形面積："+shape.m2()); } if(shape instanceof Squ){ sb.append("正方形周長(zhǎng)："+shape.m1()+"\n"+"正方形面積："+shape.m2()); } if(shape instanceof Circle){ sb.append("圓形周長(zhǎng)："+shape.m1()+"\n"+"圓形面積："+shape.m2()); } System.out.println(sb.toString()); } public static void main(String[] args) { print(new Rect(8，6)); print(new Circle(4.0)); } }

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