Java 類和對象7，java對象7

Java 類和對象7，java對象7

建立一個三角形類，成員變數三邊，方法求周長，建立類主類A來測試它。

 1 public class sanjiaoxing { 2  3     private double a; 4     private double b; 5     private double c; 6     double zhouchang; 7  8     public double getA() { 9         return a;10     }11 12     public void setA(double a) {13         this.a = a;14     }15 16     public double getB() {17         return b;18     }19 20     public void setB(double b) {21         this.b = b;22     }23 24     public double getC() {25         return c;26     }27 28     public void setC(double c) {29         this.c = c;30     }31 32     sanjiaoxing(double a, double b, double c) {33         this.a = a;34         this.b = b;35         this.c = c;36     }37 38     public void getZhouChang() {39         zhouchang = 0;40         if ((a + b > c && a + c > b && b + c > a) && (a >= 0 && b >= 0 && c >= 0)) {41             zhouchang = a + b + c;42         } else {43             System.out.println(this.a + "\t" + this.b + "\t" + this.c  + "三個數不能構成三角形。");44         }45         if (zhouchang != 0) {46             System.out.println(this.a + "\t" + this.b + "\t" + this.c  + "三個數成功構成三角形 ，周長=" + zhouchang);47         }48     }49 50     public static void main(String[] args) {51         sanjiaoxing s1 = new sanjiaoxing(1.4, 2.5, 3);52         s1.getZhouChang();53 54         sanjiaoxing s2 = new sanjiaoxing(1, 3, 4);55         s2.getZhouChang();56 57         sanjiaoxing s3 = new sanjiaoxing(1, 5, 5);58         s3.getZhouChang();59 60         sanjiaoxing s4 = new sanjiaoxing(3, -4, 5);61         s4.getZhouChang();62     }

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