java - 运算符 == 不能应用于 java.lang.String char

Question

我在 NetBeans Java 应用程序中没有遇到任何错误，但在将代码应用到 Android Java 项目时确实遇到了上述错误。我尝试了 if (alpha[i].equals(c)) { 但是我不会像在 NetBeans 中那样得到任何结果，NetBeans 将字符串转换为摩尔斯电码，例如SOS 到 ... --- ...

NetBeans Java 应用程序(有效，当我键入 SOS 时我得到... --- ...):

private static String toMorse(String text) {
    char[] characters = text.toUpperCase().toCharArray();
    StringBuilder morseString = new StringBuilder();
    for (char c : characters) {
        for (int i = 0; i < alpha.length; i++) {
            if (alpha[i] == c) {
                morseString.append(morse[i] + " ");
                break;
            }
        }
    }
    return morseString.toString();
}

Android Java 项目(不起作用，当我输入字符串时，我什么也得不到):

public String toMorse(String text) {
    char[] characters = text.toUpperCase().toCharArray();
    StringBuilder morseString = new StringBuilder();
    for (char c : characters) {
        for (int i = 0; i < alpha.length; i++) {
            if (alpha[i] == c) { // error is on this line
                morseString.append(morse[i] + " ");
                break;
            }
        }
    }
    return morseString.toString();
}

奇怪的是，这部分代码在 NetBeans 和 Android Studio 中都有效(当我输入 ... --- ... 我得到 SOS):

public String toEnglish(String text) {
    String[] strings = text.split(" ");
    StringBuilder translated = new StringBuilder();
    for (String s : strings) {
        for (int i = 0; i < morse.length; i++) {
            if (morse[i].equals(s)) {
                translated.append(alpha[i]);
                break;
            }
        }
    }
    return translated.toString();
}

阿尔法和莫尔斯数组:

private String[] alpha = {"A", "B", "C", "D", "E", "F", "G", "H", "I", "J",
    "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V",
    "W", "X", "y", "z", "1", "2", "3", "4", "5", "6", "7", "8",
"9", "0", " "};

private String[] morse = {".-", "-...", "-.-.", "-..", ".", "..-.", "--.",
    "....", "..", ".---", "-.-", ".-..", "--", "-.", "---", ".--.",
    "--.-", ".-.", "...", "-", "..-", "...-", ".--", "-..-",
    "-.--", "--..", ".----", "..---", "...--", "....-", ".....",
"-....", "--...", "---..", "----.", "-----", "|"};

Answer 1

问题是 alpha 是一个 String 数组，而 c 是一个字符。您正在比较 (char == string) ，这显然不像预期的那样工作。