Question

这是一个计算器的JAVA,咋在其中添加一个从键盘输入两个数字的代码

class SimpleCompute
{ //相加
public int add(String i,String j) throws NumberFormatException
{
return Integer.parseInt(i)+Integer.parseInt(j);
//返回和
}
//计算除 ARithemeticException为抛出异常类型
public int div(String i,String j) throws ArithmeticException
{
return Integer.parseInt(i)/Integer.parseInt(j);//返回商
} //计算减
public int subtract(String i,String j) throws NumberFormatException
{
return Integer.parseInt(i)-Integer.parseInt(j); //返回差
} //计算乘 NumberFormatException为抛出异常类型
public int Multiply(String i,String j) throws NumberFormatException
{
return Integer.parseInt(i)*Integer.parseInt(j);//返回积
}
}
public class ThrowsException //抛出异常类
{
public static void main(String args[])
{
SimpleCompute sc=new SimpleCompute();
try{
String num1="12";
String num2="1";
System.out.println("两数之和是："+sc.add(num1,num2));
System.out.println("两数之差是："+sc.subtract(num1,num2));
System.out.println("两数之商是："+sc.div(num1,num2));
System.out.println("两数之积是："+sc.Multiply(num1,num2));
}
catch (NumberFormatException e)
{
System.out.println("输入数据有误");
}
catch (ArithmeticException e)
{
System.out.println("除数为0，请重新输入");
}
finally {
System.out.println("程序运行结束");
}
}
}

Answer 1

//String num1="12";
//String num2="1";

Scanner scan = new Scanner(System.in);
System.out.println("请输入第一个数：");
String num1 = scan.nextLine();
System.out.println("请输入第二个数：");
String num2 = scan.nextLine();

System.out.println("两数之和是："+sc.add(num1,num2));
System.out.println("两数之差是："+sc.subtract(num1,num2));
System.out.println("两数之商是："+sc.div(num1,num2));
System.out.println("两数之积是："+sc.Multiply(num1,num2));

追问

出现错误，找不到符号。Scanner scan = new Scanner(System.in)

追答

引入一下包就好了

按 Ctrl + 1, 然后就会出现 一个 import *****,然后点一下就好了

Answer 2

Scanner scanner = new Scanner(System.in);

int i = scanner.nextInt();