[英]Correct User Input in Java
在解決問題時,基本代碼如下所示,從用戶那里獲取4種可能的輸入,並根據輸入的內容產生響應。 但是,我需要添加一個測試以驗證是否已輸入4個可能答案中的僅1個。
我知道如何比較4個輸入中的2個,但是不能一次比較所有4個,有人可以給我一個主意嗎? 我希望自己弄清楚實際的代碼,但是指向正確方向的指針將是有益的。
因此要澄清如何-如果輸入的內容不是“賬單,通函,明信片或信件”,則產生錯誤消息X
System.out.println("What type of Letter has been received?");
System.out.println("Bill, Circular, Postcard or Letter");
String Letter = kybd.nextLine();
{
if (Letter.equalsIgnoreCase("Bill"))
{
System.out.println("Bills must be paid");
}
else if (Letter.equalsIgnoreCase("Circular"))
{
System.out.println("Circulars are thrown away");
}
else if (Letter.equalsIgnoreCase("Postcard"))
{
System.out.println("Postcards are put on the wall");
}
else if (Letter.equalsIgnoreCase("Letter"))
{
System.out.println("Personal letters are read and have replies written for them");
}
}
if (Letter.equalsIgnoreCase("Bill"))
{
System.out.println("Bills must be paid");
}
else if (Letter.equalsIgnoreCase("Circular"))
{
System.out.println("Circulars are thrown away");
}
else if (Letter.equalsIgnoreCase("Postcard"))
{
System.out.println("Postcards are put on the wall");
}
else if (Letter.equalsIgnoreCase("Letter"))
{
System.out.println("Personal letters are read and have replies written for them");
}else{
System.out.println("ERROR");
}
您想在其中拋出“ else”條件語句,並且您可能希望查看try和catch塊,或者只是在“ else”條件中“拋出” NoSuchElement異常。
查看以下內容可能對您有用:
http://docs.oracle.com/javase/tutorial/essential/exceptions/throwing.html
在else語句中引發異常非常類似於我之前的回答,而try ... catch塊幾乎就是您正在談論的測試。 因此,它可能看起來像這樣:
try
{
Letter != "Bill" //not exactly how it'd look, but this is a general idea on what you'd do here
}
catch (NoSuchElementException e)
{
System.out.println("Not a valid input.");
}
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.