题解 | #简单计算器#
简单计算器
http://www.nowcoder.com/practice/b8f770674ba7468bb0a0efcc2aa3a239
import java.util.Scanner;
import java.lang.String;
public class Main{
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
String str=sc.nextLine();
String[] strs=str.split("[+\\-*/]");
if(strs.length<2)//先判断再分
{
System.out.println("Invalid operation!");
}else{
double a=Double.parseDouble(strs[0]);
String F=str.substring(strs[0].length(),strs[0].length() + 1);
double b=Double.parseDouble(strs[1]);
switch(F)
{
case "+":System.out.printf("%.4f+%.4f=%.4f",a,b,(a+b));break;
case "-":System.out.printf("%.4f-%.4f=%.4f",a,b,(a-b));break;
case "*":System.out.printf("%.4f*%.4f=%.4f",a,b,(a*b));break;
case "/":
if(b==0)
{
System.out.println("Wrong!Division by zero!");break;
}else{
System.out.printf("%.4f/%.4f=%.4f",a,b,(a/b));break;
}
}
}
}
}
