学习笔记：测试三角形类

参考书目：C/C++规范设计简明教程，P316

目的：编写一个三角形类，测试类的使用

第一步：建立工程，添加Triangle类

头文件为：

#pragma once
#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <stdio.h>
#include <math.h>
#include <string.h>
using namespace std;

class Triangle
{
private:
	float fA;	//三边
	float fB;
	float fC;
public:
	Triangle();
	bool setSideLength(float a, float b, float c);
	float getArea();
};

源文件为Triangle.cpp：

#include "Triangle.h"

Triangle::Triangle()
{
	fA = 0; 
	fB = 0;
	fC = 0;
}

bool Triangle::setSideLength(float a, float b, float c)
{
	if ((a + b > c) && (a + c > b) && (b + c > a))
	{
		fA = a;
		fB = b;
		fC = c;
		return true;
	}
	else
	{
		cout << "Wrong";
		return false;
	}
}
float Triangle::getArea()
{
	float fT = fA + fB + fC;
	return sqrt(fT * (fT - fA)* (fT - fB)* (fT - fC));
}

第二步：主文件

//测试三角形类

#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <stdio.h>
#include <math.h>
#include <string.h>
#include "Triangle.h"
using namespace std;
int main()
{
	cout << "Hello World!\n";
	Triangle triangle;
	bool bResult = triangle.setSideLength(3, 4, 5);
	if (bResult == true)
	{
		cout << "面积" << triangle.getArea();
	}



	getchar();
}

运行结果如下：