2019年9月16日课堂随机出题

 （1）源代码

import java.util.*;
public class FourFundamental {
    public static void main(String[] args) {
        
        int i;
        Random R = new Random();
        
        for(i=0;i<30;i++) {
            switch(R.nextInt(4)+1) {
            case 1:
                jia();
                break;
            case 2:
                jian();
                break;
            case 3:
                cheng();
                break;
            case 4:
                chu();
                break;
            }
            
            
        }
        
        



    }
    public static void jia() {
        Random T = new Random();
        Random R = new Random();
        System.out.println(T.nextInt(101)+" + "+R.nextInt(101)+" = ");
    }
    public static void jian() {
        Random T = new Random();
        Random R = new Random();
        System.out.println(T.nextInt(101)+" - "+R.nextInt(101)+" = ");
    }
    public static void cheng() {
        Random T = new Random();
        Random R = new Random();
        System.out.println(T.nextInt(101)+" * "+R.nextInt(101)+" = ");
    }
    public static void chu() {
        Random T = new Random();
        Random R = new Random();
        System.out.println(T.nextInt(101)+" / "+R.nextInt(101)+" = ");
    }
}

（2）输出结果