Question

我收到错误：

error: bad operand types for binary operator '*'
if ((monthD * dayD).equals("yearD"))    
            ^
first type:  String
second type: String

代码的要点是查看月份和日期是否等于乘以的年份。

这是我的代码：

// Month
String monthD;
System.out.print("What is the month? (For example, August would inserted as '08') ");
monthD = userInput.nextLine();

// Day
String dayD;
System.out.print("What is the day? (For example, the 10th of the month is inserted as '10') ");
dayD = userInput.nextLine();

// Year
String yearD;
System.out.print("What is the year? (For example, 1998 is inserted as '98') ");
yearD = userInput.nextLine();

// Is this date magic?
if ((monthD * dayD).equals("yearD"))
{ 
    System.out.print("This date is magic!");
} 
else
{ 
    System.out.print("This date is not magic!");
}

Answer 1

你不能拥有String数据类型＆＃39; *＆＃39; （乘法）目的。而是使用int类型。

Answer 2

您需要使用Integer.parseInt(String)将字符串转换为整数。用try / catch环绕以检查不是真正的整数。并且你甚至想要做什么，只需使用java.util.Date中的new Date()来获取日期

二元运算符的坏操作数类型＆＃39; *＆＃39;

2 个答案: