Java:从方法返回字符串

Question

我想指出，我对 Java 还很陌生，这就是为什么我可能会犯一些愚蠢的错误。

我有一个名为“Characters”的类，它由 4 个变量和多个方法组成。所有变量都是私有(private)的，因此根据我所读到的内容，我需要使用方法对它们执行任何操作。

其中一种方法应该以字符串形式返回变量之一，但是我不断从 Eclipse 和运行它时收到错误。 “此方法必须返回“String”类型的结果。错误发生在该方法的第一行:

public String displayStats(String option) {
    switch (option) {
    case "charName":
        System.out.println(charName);
        return charName;
    case "charHealth":
        System.out.println(charHealth);
        String charHealth2 = Integer.toString(charHealth);
        return charHealth2;
    case "charMana":
        System.out.println(charMana);
        String charMana2 = Integer.toString(charMana);
        return charMana2;
    case "charStamina":
        System.out.println(charStamina);
        String charStamina2 = Integer.toString(charStamina);
        return charStamina2;
    default:
        System.out.println("Error on default");}
}

}

全类:

package basics;

public class Characters {

    private String charName = "";
    private int charHealth = 0;
    private int charMana = 0;
    private int charStamina = 0;

    public void summoner(Characters player) {
        player.charName = "Summoner";
        player.charHealth = 80;
        player.charMana = 150;
        player.charStamina = 50;}

    public void sentinel(Characters player) {   
        player.charName = "Sentinel";
        player.charHealth = 200;
        player.charMana = 50;
        player.charStamina = 100;}

    public void beserker(Characters player) {
        player.charName = "Beserker";
        player.charHealth = 100;
        player.charMana = 0;
        player.charStamina = 200;}

    public void mage(Characters player) {
        player.charName = "Mage";
        player.charHealth = 80;
        player.charMana = 200;
        player.charStamina = 20;}   

    public String displayStats(String option) {
        switch (option) {
        case "charName":
            System.out.println(charName);
            return charName;
        case "charHealth":
            System.out.println(charHealth);
            String charHealth2 = Integer.toString(charHealth);
            return charHealth2;
        case "charMana":
            System.out.println(charMana);
            String charMana2 = Integer.toString(charMana);
            return charMana2;
        case "charStamina":
            System.out.println(charStamina);
            String charStamina2 = Integer.toString(charStamina);
            return charStamina2;
        default:
            System.out.println("Error on default");}
    }

}

Answer 1

在 switch 语句的默认情况下，您不会返回任何内容，这意味着该方法有可能(无论多么小)不知道要返回什么。