java - " expected"Java 编译错误

Question

我在这一行收到“<identifier> expected ”错误......

  private static String getReducedISBN(char 'x') {

...这段代码....

public class CheckISBN7 {

//private static String originalISBN;  // class variable

public static void main(String[] args) {
    // Prompt the user to enter an ISBN
    SimpleIO.prompt("Enter ISBN: ");
    String originalISBN = SimpleIO.readLine();

    // Get the ISBN number without the dashes
    String reducedISBN = getReducedISBN('-');

    // Get the computed check digit
    int computedCheckDigit = getCheckDigit(reducedISBN);

    // Display check digit entered by the user
    System.out.println("Check digit entered: " + originalISBN.charAt(12));

    // Display computed check digit
    System.out.println("Check digit computed: " + computedCheckDigit);
}

private static String getReducedISBN(char 'x') {
    SimpleIO.prompt("Enter ISBN: ");
    String originalISBN = SimpleIO.readLine();
    int dashPos1 = originalISBN.indexOf("x");
    int dashPos2 = originalISBN.indexOf("x", dashPos1 + 1);
    String reducedISBN = originalISBN.substring(0, dashPos1) +
            originalISBN.substring(dashPos1 + 1, dashPos2) +
            originalISBN.substring(dashPos2 + 1, 11);
    return reducedISBN;
}

private static int getCheckDigit(String reducedISBNParameter) {
    int total = 0;
    final String digits = "0123456789X";
    for(int i = 0, j = 10; i <= 8; i++, j++) {
        total += j *
                (Integer.parseInt(reducedISBNParameter.substring(i, i + 1)));
    }
    int checkDigit = 10 - ((total - 1) % 11);
    int computedCheckDigit = digits.charAt(checkDigit);
    return computedCheckDigit;
    }
}

无法真正找出问题，任何帮助将不胜感激。

Answer 1

'x' 不是一个标识符(变量或其他)，它是一个文字字符。同样，“x”是一个文字字符串。将 char 'x' 替换为 Character x，将 "x" 替换为 x.toString() 即可得到您想要的内容想要。