四则运算 测试与封装

import java.util.Scanner;
public class Calculator
 {
public static void main(String[] args) 
{
    System.out.println("运算符是 +，-，*，/");
    Scanner sc = new Scanner(System.in);
    System.out.println("请输入第一个数：");
    String aStr = sc.nextLine();
    System.out.println("请输入第二个数：");
    String bStr = sc.nextLine();
    System.out.println("请输入运算符：");
    String cc = sc.nextLine();
    double a = Double.parseDouble(aStr);
    double b = Double.valueOf(bStr);

Core core = new Core();
core.calc(cc, a, b);
}
}
public class Core
 {
public void calc(String cc, double a, double b)
 {
if (cc.equals("+"))
 {
System.out.println(a + b);
} else if (cc.equals("-")) 
{
System.out.println(a - b);
} else if (cc.equals("*"))
 {
System.out.println(a * b);
} else if (cc.equals("/")) 
{
if (b != 0) 
{
System.out.println(a / b);
} else 
{
System.out.println("分母不能为零！");
}
} else 
{
System.out.println("输入不符合要求！");
}
}
}

 结对同学：莫俊余http://www.cnblogs.com/mjysok/