尝试确定字符串在Java中是否仅包含字母

Question

我的代码如下：

} 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是一个布尔值，thisLetter是一个Character类型（不是char）。 由于某种原因，编译时出现以下错误：

 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 。 返回的值将由编译器自动装箱成Character

Character没有方法isLetter() ，相反，您应该尝试...

letter = Character.isLetter(thisLetter);

当然，假设这thisLetter是一个char ...

有关更多详细信息，请查阅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;
    }
}