第4次作业类测试代码+043+杨晨宇

triangle的代码：

package triangle;

import java.text.DecimalFormat;

public class Triangle {
	public Triangle() {

	}

	/*
	 * 判断三角形的类型
	 */
	public String triangleshape(int a, int b, int c) {
		if ((a < 1 || a > 100) || (b < 1 || b > 100) || (c < 1 || c > 100)) {
			return "边的值不在范围内！";
		} else if ((a >= b + c) || (b >= a + c) || (c >= a + b)) {
			return "不构成三角形！";
		} else if (a == b || a == c || b == c) {
			if (a == b && a == c) {
				return "等边三角形！";
			} else {
				return "等腰三角形！";
			}
		} else if (a * a == b * b + c * c || b * b == a * a + c * c || c * c == b * b + a * a) {
			return "直角三角形";
		} else {
			return "一般三角形";
		}
	}

	/*
	 * 是否是三角行
	 */
	public boolean istriangle(int a, int b, int c) {
		if (("边的值不在范围内！".equals(triangleshape(a, b, c)) || ("不构成三角形！".equals(triangleshape(a, b, c))))) {
			return false;
		}
		return true;
	}

	/*
	 * 周长
	 */
	public int perimeter(int a, int b, int c) {
		if (istriangle(a, b, c)) {
			return a + b + c;
		} else {
			return 0;
		}
	}

	/*
	 * 面积
	 */
	public String erea(int a, int b, int c) {
		if (istriangle(a, b, c)) {
			double l = 0, s = 0;
			l = (a + b + c) * 0.5;
			s = Math.sqrt(l * (l - a) * (l - b) * (l - c));
			DecimalFormat df = new DecimalFormat("#.00");
			String erea = df.format(s);
			return erea;
		} else {
			return "";
		}
	}

}

　Version

package triangle;

import java.text.DecimalFormat;

public class Triangle {
	public Triangle() {

	}

	/*
	 * 判断三角形的类型
	 */
	public String triangleshape(int a, int b, int c) {
		if ((a < 1 || a > 100) || (b < 1 || b > 100) || (c < 1 || c > 100)) {
			return "边的值不在范围内！";
		} else if ((a >= b + c) || (b >= a + c) || (c >= a + b)) {
			return "不构成三角形！";
		} else if (a == b || a == c || b == c) {
			if (a == b && a == c) {
				return "等边三角形！";
			} else {
				return "等腰三角形！";
			}
		} else if (a * a == b * b + c * c || b * b == a * a + c * c || c * c == b * b + a * a) {
			return "直角三角形";
		} else {
			return "一般三角形";
		}
	}

	/*
	 * 是否是三角行
	 */
	public boolean istriangle(int a, int b, int c) {
		if (("边的值不在范围内！".equals(triangleshape(a, b, c)) || ("不构成三角形！".equals(triangleshape(a, b, c))))) {
			return false;
		}
		return true;
	}

	/*
	 * 周长
	 */
	public int perimeter(int a, int b, int c) {
		if (istriangle(a, b, c)) {
			return a + b + c;
		} else {
			return 0;
		}
	}

	/*
	 * 面积
	 */
	public String erea(int a, int b, int c) {
		if (istriangle(a, b, c)) {
			double l = 0, s = 0;
			l = (a + b + c) * 0.5;
			s = Math.sqrt(l * (l - a) * (l - b) * (l - c));
			DecimalFormat df = new DecimalFormat("#.00");
			String erea = df.format(s);
			return erea;
		} else {
			return "";
		}
	}

}

　主函数MAIN

package triangle;

import java.text.DecimalFormat;

public class Triangle {
	public Triangle() {

	}

	/*
	 * 判断三角形的类型
	 */
	public String triangleshape(int a, int b, int c) {
		if ((a < 1 || a > 100) || (b < 1 || b > 100) || (c < 1 || c > 100)) {
			return "边的值不在范围内！";
		} else if ((a >= b + c) || (b >= a + c) || (c >= a + b)) {
			return "不构成三角形！";
		} else if (a == b || a == c || b == c) {
			if (a == b && a == c) {
				return "等边三角形！";
			} else {
				return "等腰三角形！";
			}
		} else if (a * a == b * b + c * c || b * b == a * a + c * c || c * c == b * b + a * a) {
			return "直角三角形";
		} else {
			return "一般三角形";
		}
	}

	/*
	 * 是否是三角行
	 */
	public boolean istriangle(int a, int b, int c) {
		if (("边的值不在范围内！".equals(triangleshape(a, b, c)) || ("不构成三角形！".equals(triangleshape(a, b, c))))) {
			return false;
		}
		return true;
	}

	/*
	 * 周长
	 */
	public int perimeter(int a, int b, int c) {
		if (istriangle(a, b, c)) {
			return a + b + c;
		} else {
			return 0;
		}
	}

	/*
	 * 面积
	 */
	public String erea(int a, int b, int c) {
		if (istriangle(a, b, c)) {
			double l = 0, s = 0;
			l = (a + b + c) * 0.5;
			s = Math.sqrt(l * (l - a) * (l - b) * (l - c));
			DecimalFormat df = new DecimalFormat("#.00");
			String erea = df.format(s);
			return erea;
		} else {
			return "";
		}
	}

}

　　结果截图：