public static void main(String[] args) {

for (; ; ) {

Scanner scanner=new Scanner(System.in);

Scanner scanner1=new Scanner(System.in);

Scanner scanner2=new Scanner(System.in);

System.out.println(“请输入第一个数”);

int n = scanner.nextInt();

System.out.println(“请输入算法:1.加2.减3.乘4.除”);

int ffa = scanner1.nextInt();

System.out.println(“请输入第二个数”);

int m = scanner2.nextInt();

if (ffa==1){

System.out.println(“结果是”+add(n,m));

}else if(ffa==2){

System.out.println(“结果是”+jian(n,m));

}else if(ffa==3){

System.out.println(“结果是”+ cheng(n,m));

}else if(ffa==4){

System.out.println(“结果是”+chu(n,m));

}else {

System.out.println(“不属于”);

}

}

}

public static int add(int n,int m){

return n+m;

}

public static int jian(int n,int m){

return n-m;

}

public static int cheng(int n,int m){

return n*m;

}

public static double chu(int n,int m){

return (double) n/m; //除法运算

}