四则运算 测试与封装5.1

package test1;

import java.util.*;
public class Si {

/**
* @param args
*/
public static void main(String[] args) {
int a=0,b=0;
Scanner sc = new Scanner(System.in);
System.out.println("请输入你的题量；");
int c=sc.nextInt();

Feng feng = new Feng();
feng.calc(c, a, b);
}
}
package test1;
import java.util.Scanner;
public class Feng {
public void calc(int c, int a, int b) {
Scanner sc = new Scanner(System.in);
for(int i=0;i<c;i++)
{
int s=1+(int)(Math.random()*4);
switch(s)
{
case 1:
int k;
a=1+(int)(Math.random()*100);
b=1+(int)(Math.random()*100);
System.out.println(a+"+"+ b + "=");
k=sc.nextInt();
if(k==a+b)
System.out.println("答案正确；");
else System.out.println("答案错误,正确答案为"+(a+b));
break;
case 2:
int l=0;
a=1+(int)(Math.random()*100);
b=1+(int)(Math.random()*100);
System.out.println(a+"-"+ b + "=");
l=sc.nextInt();
if(l==a-b)
{
System.out.println("答案正确；");
if(a<b)
System.out.println("改答案为负数；");
}
else System.out.println("答案错误,正确答案为"+(a-b));
break;
case 3:
int m;
a=1+(int)(Math.random()*10);
b=1+(int)(Math.random()*10);
System.out.println(a+"*"+ b + "=");
m=sc.nextInt();
if(m==a*b)
System.out.println("答案正确；");
else System.out.println("答案错误,正确答案为"+(a*b));
break;
case 4:
int n;
a=1+(int)(Math.random()*10);
b=1+(int)(Math.random()*10);
System.out.println(a+"/"+ b + "=");
n=sc.nextInt();
if(n==a/b)
System.out.println("答案正确；");
else System.out.println("答案错误,正确答案为"+(a/b));
break;
}
}
}
}