Eclipse 'Syntax error on token ",", Expression expected after this token'，我的语法哪里错了？

Question

package MainFunction;


public class Main {

public static void main(String[] args) {
    // TODO Auto-generated method stub
    Gun m_one = new Gun("M1", 30, ["Bleeding"], "semi-auto", ".15 cal", "lead", 8);
    System.out.println("Java Works.");
}

}

m_one 中存在语法错误。它说：标记“,”的语法错误，此标记后应有表达式

我不明白这是从哪里来的。这是我的构造函数：

package MainFunction;




 public class Weapon {
    Weapon(String name, int damage, String[] effects){
        this.name = name;
        this.damage = damage;
        this.effects = effects;
    }
    private int damage;
    public String name;
    private String[] effects;
    public void addEffect(String effect){
        effects[effects.length] = effect;
    }
}
    class Gun extends Weapon {
    private String type;
    public String name;
    private int damage;
    public String[] effects;
    private String ammoType;
    private String bulletMaterial;
    private int barrelLength;
    private String fireType;
    Gun( String name, int damage, String[] effects, String fireType, String ammoType, String bulletMaterial, int barrelLength) {
        super(name, damage, effects);
        // TODO Auto-generated constructor stub
        this.name = name;
        this.damage = damage;
        this.effects = effects;
        this.fireType = fireType;
        this.ammoType = ammoType;
        this.type = "ranged";
        this.bulletMaterial = bulletMaterial;
        this.barrelLength = barrelLength;
    }

}



class Sword extends Weapon {
    private String type;
    public String name;
    private int damage;
    public String[] effects;
    private int bladeLength;
    private int hiltLength;
    private String bladeMaterial;
    Sword(String name, int damage, String[] effects, int barrelLength, int hiltLength, String bladeMaterial){
        super(name, damage, effects);
        this.name = name;
        this.damage = damage;
        this.effects = effects;
        this.type = "melee";    
        this.bladeLength = bladeLength;
        this.hiltLength = hiltLength;
        this.bladeMaterial = bladeMaterial;
    }
}

构造函数returns 没有错误，但是当我使用它时却出错了。有什么问题？

Answer 1

您需要在 m_one 的声明中使用大括号而不是方括号，围绕 "Bleeding"。

Answer 2

您正在尝试使用以下表达式创建和传递字符串数组：

["Bleeding"]

但是，这不是用于创建数组的 Java 语法。您必须显式创建数组，指定类型，以及包含内容的大括号 {}。

new String[] {"Bleeding"}

如果您愿意，您可以拥有多个元素：

new String[] {"Bleeding", "Damaging"};

此外，稍后在 Weapon 的 addEffect 方法中，您尝试通过分配超出数组长度的元素来增加数组长度。

effects[effects.length] = effect;

在 Java 中，数组一旦创建就具有固定大小，因此这将引发 ArrayIndexOutOfBoundsException。如果您需要可变长度数组，请将 String[] 替换为 List<String>。首先，在构造函数中：

Weapon(String name, int damage, List<String> effects){

然后在声明时 effects:

List<String> effects;

然后在定义addEffect时：

effects.add(effect);

无需在 main 中创建数组，您需要创建 List 的实现并将其传入。

List<String> effects = new ArrayList<>();
effects.add("Bleeding");
effects.add("Damaging");
Gun m_one = new Gun("M1", 30, effects, "semi-auto", ".15 cal", "lead", 8);

Eclipse 'Syntax error on token ",", Expression expected after this token'，我的语法哪里错了？

Eclipse 'Syntax error on token ",", Expression expected after this token', where is my syntax wrong?

java

eclipse

object

syntax-error