结对编程四则运算

JAVA四则运算小demo

package mirrorliAndhuangqi;

import java.lang.Math;
public class Operating {

    //声明第一个操作数、第二个操作数、操作符、结果
    private static int firstNum;
    private static int secondNum;
    private static String operator;
    //private static int result;

    //生成第一个操作数
    public int firstNum(){
        firstNum = (int)(1+Math.random()*99);//第一个操作数1~100
        return firstNum;
    }

    //生成第二个操作数
    public int secondNum(){
        secondNum = (int)(1+Math.random()*99);//第二个操作数1~100
        return secondNum;
    }

    //返回操作符
    public String operator(){
        int flag;
        flag = (int)(1+Math.random()*3);//1~4分别对应+-*/
        switch(flag){
            case 1:
                operator = "+";
                break;
            case 2:
                operator = "-";
                break;
            case 3:
                operator = "*";
                break;
            case 4:
                operator = "/";
                break;
            default:
                break;
        }
        return operator;
    }

    //返回结果
/*  public int result(){
        if(operator == "+"){
            return firstNum+secondNum;
        }else if(operator == "-"){
            return firstNum-secondNum;
        }else if(operator == "*"){
            return firstNum*secondNum;
        }else if(operator == "/"){
            return firstNum/secondNum;
        }else{
            return 0;
        }
    }
    */
    public String expression(){
        return firstNum()+operator()+secondNum();
    }
}

package mirrorliAndhuangqi;

public class Test {
    public static void main(String[] args){
        //查重操作。。搞忘封装了
        //存放30个表达式的字符数组
        String expree[]=new String[30];
        Operating opera = new Operating();
        //将第一个随机表达式存入数组
        expree[0]=opera.expression();
        for(int i=1;i<30;i++){
            //判断是否能跳出while循环
            boolean flag = true;
            //若有一个新表达式则加入数组并跳出循环
            while(flag){
                String str = opera.expression();
                int gg = 0;
                //遍历表达式数组expree，查重
                for(int k=0;kif(str == expree[k]){
                        break; 
                    }else{
                        gg++;
                    }
                }   
                //如果之前所有的都没重复则添加到数组
                if(gg == i){
                    flag = false;
                    expree[i] = str;
                }
            }       
        }
        for(int i=0;i<30;i++){
            System.out.println(expree[i]+"=?");
        }
//      
    }
}