java - While(matcher.find()) - 错误 - 不起作用

Question

我需要排序帮助

我不知道为什么当我有字符串“3*3”时，matcher.find()会跳转

代码:

    public void delSin_Cos_Tan()
            {
                o = new ArrayList<>();
                String aDate = "3*3";
                Pattern datePattern = Pattern.compile("((sin|cos|tan|sinh|cosh|tanh|asin|acos|atan)\\((.+)\\))"); 
//Operat.Sin_Cos_Tan.Patter = ((sin|cos|tan|sinh|cosh|tanh|asin|acos|atan)\((.+)\))
                Matcher matcher = datePattern.matcher(aDate);
                Log.d(TAG,"Sin Startz");
                Log.d(TAG,"Sin " + Aufgabe);
                while (matcher.find());
                {
                    Log.e(TAG,matcher.group(1)); // there is the Error, but withe the String "3*3" an i don't konw why it is jump inside the while  
                    String Gesammt = matcher.group(1);
                    String TYP = matcher.group(2);
                    String Inklammer = matcher.group(3);

                    Log.d(TAG, String.valueOf("------------------------"));
                    Log.d(TAG, Gesammt);
                    Log.d(TAG, Inklammer);
                    Log.d(TAG, TYP);
                    Log.d(TAG, String.valueOf("------------------------"));
               }
            }

我的完整代码:http://pastebin.com/jWN1ghfz

Answer 1

在 while 循环之后有一个 ; 。这就是为什么你的完整 block 总是会被执行!

while (matcher.find()); 应该是 while (matcher.find()) (没有 ;)

因为

while (matcher.find());
{
 //...
}

与

相同

while (matcher.find()){
;
}

{
 //...
}