好了,你测试一下咯!
public interface ShapeArea {//定义ShapeArea接口
public double getArea();//double getArea( ):求一个形状的面积
public double getPerimeter();//启袜 Double getPerimeter( ):求一个肢埋形状的周长。
}
public class MyTriangle implements ShapeArea {
double x,y,z,s;//x,y,z :double型,表示三角形的三条边
public MyTriangle(double x, double y, double z) {//方法:MyTriangle(double x, double y, double z):构造函数,给三条边和s赋值;
this.x = x;
this.y = y;
this.z = z;
this.s = (x+y+z)/2;
}
@Override
public double getArea() {
return Math.sqrt(this.s*(this.s-this.x)*(this.s-this.y)*(this.s-this.z));
}
@Override
public double getPerimeter() {
return (x+y+z);
}
@Override
public String toString() {
System.out.print(此三角形的面积和周悄饥激长为:);
return this.getArea()+、+this.getPerimeter();
}
}
public class Test {//测试类
public static void main(String[] args) {
MyTriangle myTriangle = new MyTriangle(3, 4, 5);
System.out.println(myTriangle);
}
}
额热风风热二恶突然人员突然一天
import java.util.ArrayList;
import java.util.Collection;
public class StringUtils {
public static Integer[] positions(String shortStr,String longStr){
Collection<Integer> positions = new ArrayList<Integer>();
int index = 0;
while((index=longStr.indexOf(shortStr, index)+1)!=0){
positions.add(index-1);
}
return positions.toArray(new Integer[positions.size()]);
}
public static boolean isHuiWen(String str){
byte[] bytes = str.getBytes();
for(int i=0;i<bytes.length/2;i++){
if(bytes[i]==bytes[bytes.length-i-1]){
continue;
}else{
return false;
}
}
return true;
}
public static String getName(String email){
return email.substring(0, email.indexOf(@));
}
}
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