28 lines
524 B
Java
28 lines
524 B
Java
package chapter4.demo45;
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/**
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* 圆形类
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* 必需实现 Shape 接口中的 getArea 和 getPerimeter 方法
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*/
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public class Circle implements Shape {
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// 半径
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private double radius = 0;
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private final static double PI = 3.14;
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// 有参构造
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public Circle(double radius) {
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this.radius = radius;
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}
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// 返回面积
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public double getArea() {
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return PI * radius * radius;
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}
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// 返回周长
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public double getPerimeter() {
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return 2 * PI * radius;
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}
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}
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