下面我有一段代碼,我不會工作。我在我的主要方法得到輸入,然後將該輸入傳遞到另一個方法來檢查驗證。但它並沒有真正檢查正確。如果我爲month
和day
輸入99
,我希望它給我Check Month
的消息。爲什麼我沒有得到正確的返回信息?
相反,我得到: THIS THIS
如果我的月輸入02
和99
的一天,我希望它給我留言:Check day
。相反,我得到THIS THIS
如果我輸入02
兩個,我期望它運行並繼續運行其他方法。相反,我得到THIS THIS
。
public class Date {
private Calendar parsedDate;
public static void main(String[] args)
{
Date main = new Date();
System.out.println("Enter a date (use the format -> (MM/DD/YYYY)");
//declare Scanner
Scanner in = new Scanner (System.in);
System.out.println("Enter a month (MM): ");
String month = in.nextLine();
System.out.println("Enter a day (DD): ");
String day = in.nextLine();
System.out.println("Enter a year (YYYY): ");
String year = in.nextLine();
if (main.isValidDate(month, day, year) == true)
{
main.newFormat(month, day, year);
main.isLeapYear(year);
main.dayNumber(month, day);
}
else if (main.isValidDate(month, day, year) == false)
{
System.out.println("Invalid Input");
}
}//end of main
private boolean isValidDate(String month, String day, String year)
{
//check month
if(month == "01" || month == "03" || month == "04" ||
month == "05" || month == "06" || month == "07" || month == "08" ||
month == "09" || month == "10" || month == "11" || month == "12")
{
//check day
if(day == "01" || day == "02" || day == "03" || day == "04" ||
day == "05" || day == "06" || day == "07" || day == "08" ||
day == "09" || day == "10" || day == "11" || day == "12" ||
day == "13" || day == "14" || day == "15" || day == "16" ||
day == "17" || day == "18" || day == "19" || day == "20" ||
day == "21" || day == "22" || day == "23" || day == "24" ||
day == "25" || day == "26" || day == "27" || day == "28" ||
day == "29" || day == "30" || day == "31")
{
return true;
}
else
{
System.out.println("Check Day");
return false;
}
}//end of check month
else if (month == "02")
{
if (day == "28" || day == "29")
{
return true;
}
}//end of month 2
else
{
System.out.println("THIS");
return false;
}
parsedDate = null;// if it's valid set the parsed Calendar object up.
return true;
}//end of isValidDate
正如喬恩寫的,你應該聲明常量並以這種方式比較'if(month == JANUARY)'等。這更清楚。 – pepuch
如果我輸入了錯誤的月份,它會打印兩次「Check Month」!爲什麼是這樣? –
@DwellingPlace:那麼你現在調用'isValidDate'兩次。不要這樣做。 –