我想搜索一個文件,一個小的,我輸入的字符串,然後只輸出該行上的double值。每次嘗試某些東西時我都會收到錯誤消息。此外,我試圖避免使用循環,所以它有點具有挑戰性(我知道有一個while循環,但我會處理接下來..任何幫助將不勝感激。哦,是的,文本文件看起來像這樣(這兩個頂級股票。行情)我得到一個numberformatexception
AAPL 101.50
MSFT 45.84
File file = new File("stocks.txt");
Scanner ticker = new Scanner(System.in);
Scanner scan = new Scanner(file);
String phone;
System.out.print("\nEnter a stock ticker: ");
String that = ticker.next();
while(scan.hasNext())
{
phone = scan.nextLine();
//double b = Double.parseDouble(phone);
if(phone.contains(that))
System.out.println(phone + "\n");
}
one of the errors is:
Enter a stock ticker: AAPL
Exception in thread "main" java.util.InputMismatchException
at java.util.Scanner.throwFor(Scanner.java:864)
at java.util.Scanner.next(Scanner.java:1485)
at java.util.Scanner.nextDouble(Scanner.java:2413)
at hw01a.java.Hw01aJava.main(Hw01aJava.java:36)
Java Result: 1
BUILD SUCCESSFUL (total time: 4 seconds)
the other is:
Enter a stock ticker: AAPL
Exception in thread "main" java.lang.NumberFormatException: For input string: "AAPL 101.50"
at sun.misc.FloatingDecimal.readJavaFormatString(FloatingDecimal.java:2043)
at sun.misc.FloatingDecimal.parseDouble(FloatingDecimal.java:110)
at java.lang.Double.parseDouble(Double.java:538)
at hw01a.java.Hw01aJava.main(Hw01aJava.java:34)
Java Result: 1
BUILD SUCCESSFUL (total time: 4 seconds)
什麼錯誤,你會得到什麼線? –
當我嘗試打印出手機的值時,我只出現錯誤。 – Andrew
向我們顯示異常消息。整個東西。恰恰。 –