创建一个分数类，实现分数的加减乘除

要求：实现两个分数的加、减、乘、除；四个功能

思路：分数类可想而知属性就只有分子和分母，限制条件分母不能为0,做分数的加减法有可能要先约分在通分，我这里用辗转相除法求出最大公约数。之后就可以一一完善这四个功能了。(代码如下

public class FenShu {
	private long molecular;// 分子
	private long denominator;// 分母

	public long getMolecular() {
		return molecular;
	}

	public long getDenominator() {
		return denominator;
	}

	//首先判断输入是否合法，然后调用gaibian()这个方法求取最大公约数
	public FenShu(long molecular, long denominator) {
		this.molecular = molecular;
		if (denominator == 0) {
			System.out.print("分母不能为零");
		} else {
			this.denominator = denominator;
		}
		gaibian();
	}

	//求最大公约数
	private FenShu gaibian() {
		long gcd = this.gYueShu(this.molecular, this.denominator);
		//这里进行约分
		this.molecular /= gcd;
		this.denominator /= gcd;
		//返回约分后的分数
		return this;
	}

	/**
	 * 最大公约数
	 * 
	 * @param a
	 * @param b
	 * @return
	 */
	private static long gYueShu(long a, long b) {
		while (b != 0) {
			long temp = a % b;
			a = b;
			b = temp;
		}
		long gyueshu = a;
		return gyueshu;
	}

	/**
	 * 加法
	 * 
	 * @param second
	 * @return
	 */
	public FenShu add(FenShu fenShu) {
		//返回两个分数相加的结果
		return new FenShu(this.molecular * fenShu.denominator
				+ fenShu.molecular * this.denominator, this.denominator
				* fenShu.denominator);
	}

	/**
	 * 减法
	 * 
	 * @param second
	 * @return
	 */
	public FenShu subtraction(FenShu fenShu) {
		return new FenShu(this.molecular * fenShu.denominator
				- fenShu.molecular * this.denominator, this.denominator
				* fenShu.denominator);
	}

	/**
	 * 乘法
	 * 
	 * @param second
	 * @return
	 */
	public FenShu multiplication(FenShu fenShu) {
		return new FenShu(this.molecular * fenShu.molecular, this.denominator
				* fenShu.denominator);
	}

	/**
	 * 除法
	 * @param fenShu
	 * @return
	 */
	public FenShu division(FenShu fenShu){
		return new FenShu(this.molecular*fenShu.denominator, this.denominator*fenShu.molecular);
		
	}
	/**
	 * toString()方法打印输出
	 */
	@Override
	public String toString() {
		return "运算结果 [" + molecular + "/" + denominator + "]";
	}}

测试代码：

public static void main(String[] args) {
		// TODO Auto-generated method stub
		FenShu a = new FenShu(2, 9);
		FenShu b = new FenShu(2, 3);
		System.out.println("加法"+a.add(b));
		System.out.println("减法"+a.subtraction(b));
		System.out.println("乘法"+a.multiplication(b));
		System.out.println("除法"+a.division(b));
	}

运行结果：

ok,欢迎大家评论、指导。