无法在Switch语句中实例化字符串数组- Java

Question

出于某种原因，String[]冠军没有被实例化，我似乎不明白为什么

champs = new String[]{ "BLAH", "BLAH", "BLAH"};不应该初始化数组吗？

  public static String[] getChamps() {

    String rolereturn = ChampSelect.getRoles();

    //Switch to Determine Champion Suggestions


    String[] champs; //String Declaration

    switch (rolereturn) {

        case "AD Carry": //AD Carry Selection Options
            champs = new String[]{ "Ashe", "Caityln", "Draven", "Ezreal", "Kog'Maw", "Sivir", "Twitch", "Varus", "Vayne" };
            break;

        case "AP Carry": //AP Carry Selection Options
            champs = new String[]{ "Diana", "Evelyn", "Kassadin", "Kennen" };
            break;

        case "Support": //Support Selection Options
            champs = new String[]{ "Janna", "Nunu", "Shen", "Soraka", "Taric", };
            break;

        case "AP Jungle": //AP Jungle Selection Options
            champs = new String[]{ "Diana", "Fiddlesticks" };
            break;

        case "AD Jungle": //AD Jungle Selection Options
            champs = new String[]{ "Kha'Zix", "Nocturne", "Rengar", "Udyr", "Warwick", };
            break;

        case "AP Top": //AP Top Selection Options
            champs = new String[]{ "Akali", "Cho'Gath", "Kennen", "Malphite", "Shen", "Singed", "Teemo" };
            break;

        case "AD Top": //AD Top Selection Options
            champs = new String[]{ "Fiora", "Irelia", "Jax", "Kha'Zix", "Master Yi", "Nasus", "Nidalee", "Rengar", "Zed" };
            break;
    }
    return champs;
}

Answer 1

你是对的，如果调用其中一个case语句，它将初始化数组。我会在其中添加一个default，然后在调用该default时抛出。当没有匹配的case语句时，将调用默认值。看起来您已经覆盖了所有的case语句，所以使用default抛出将是一个好主意。

像这样的东西应该就行了

 default: throw new RuntimeException("SHould not be here " + rolereturn);

Answer 2

我会用Map而不是开关柜，

public static String[] getChamps() {

    Map<String,String[]> map = new HashMap();
    map.put("AD Carry",new String[]{ "Ashe", "Caityln", "Draven", "Ezreal", "Kog'Maw", "Sivir", "Twitch", "Varus", "Vayne" });
    // ... and so on for all your cases

    String rolereturn = ChampSelect.getRoles();
    if (!map.containsKey(rolereturn)) throw new IllegalArgumentException(rolereturn);

    return map.get()    
}

Answer 3

最可能的原因是rolereturns不是您想的那样的问题。您是否可以尝试在开关的末尾添加一个默认值，将数组设置为某个值，并查看是否可以这样做？

否则，只需调试并检查您是否进入了正确的行...