程序测试学习篇の程序的封装

public class test {
    private int a;
    private int b;
    int c;
    public int  add(int a,int b)
    {
    
        System.out.println(""+a);
        System.out.println(""+b);
        c = a+b;
        System.out.println("a+b="+(a+b)+"\n");
        return c;
        
    }
    public int  jian(int a,int b)
    {
        
        System.out.println(""+a);
        System.out.println(""+b);
        c=a-b;
        System.out.println("a-b="+(a-b)+"\n");
        return c;
        
        
    }
    public int Cheng(int a,int b)
    {   
        System.out.println(""+a);
        System.out.println(""+b);
        c=a*b;
        System.out.println("a*b="+(a*b)+"\n");
        return c;
    }
    public double  Chu(int a,int b)
    {
        double c;
        c=(double) (Math.round((a/b)*100/100.0));
        System.out.println(""+a);
        System.out.println(""+b);
        if(b!=0)
            System.out.println("c=a/b="+(c)+"\n");
        else
            throw new ArithmeticException();
            System.out.println("分母不能为0！");
              
            return c;
    }

    /**
     * @param args
     */
    public static void main(String[] args) {
         Test Jia=new Test();
         Jia.jia(1, 1);
         Test Jian=new Test();
         Jian.jian(2,1);
         Test cheng=new Test();
         cheng.Cheng(2,3);
         Test chu=new Test();
         chu.Chu(3,0);
         
    }

与四则运算一致，但代码看上去简洁明了，修改性较易。灵活性较强！
学到知识了！