嘗試確定字符串在Java中是否僅包含字母

Question

我的代碼如下：

} else if (words.toUpperCase().equals(words)) {
    for (int i = 0; words.length() > i; i++){
      thisLetter = words.charAt(i);
      letter = thisLetter.isLetter();
      if (!letter){
        break;
      }
    }  

letter是一個布爾值，thisLetter是一個Character類型（不是char）。 由於某種原因，編譯時出現以下錯誤：

 no suitable method found for isLetter()
method java.lang.Character.isLetter(int) is not applicable
  (actual and formal argument lists differ in length)
method java.lang.Character.isLetter(char) is not applicable
  (actual and formal argument lists differ in length)

Answer 1

代替letter = thisLetter.isLetter(); ，它返回原始char 。 返回的值將由編譯器自動裝箱成Character

Character沒有方法isLetter() ，相反，您應該嘗試...

letter = Character.isLetter(thisLetter);

當然，假設這thisLetter是一個char ...

有關更多詳細信息，請查閱Java Docs 。

Answer 2

承租人：

boolean containsOnly = true;
for (int i = 0; i < words.length(); i++) {
    char theChar = words.charAt(i);
    int index = "Java".indexOf(theChar);
    if (index < 0) {
       containsOnly = false;
       break;
    }
}