Question

我有一个类沙鼠，我已经在main方法中正确初始化了它的实例数组。现在我想要一个只需要一个参数（基本上是搜索字符串）的搜索功能。如何在搜索功能中传递沙鼠阵列而不将其作为参数传递。

public class Gerbil {
    String lab_id;
    String name;
    boolean isBite;
    public int[] eat;

    public Gerbil(int x) {
        eat = new int[x];
    }

    public String getLab_id() {
        return lab_id;
    }

    public void setLab_id(String lab_id) {
        this.lab_id = lab_id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public boolean isBite() {
        return isBite;
    }

    public void setBite(boolean isBite) {
        this.isBite = isBite;
    }

    public void setEat(int a, int b) {
        eat[a]=b;
    }

    public int getEat(int a){
        return eat[a];
    }

主方法中的沙鼠类数组的声明

Gerbil[] gerbils = new Gerbil[gerbil_no];

// initializing the Food class into the Gerbil Class

for (int x = 0; x < gerbils.length; x++) {
    gerbils[x] = new Gerbil(types);
}

Answer 1

使用此代码在类范围内声明数组（在所有函数之外）：

private static Gerbil[] gerbils;

现在，在主函数中使用size初始化它：

gerbils = new Gerbil[gerbil_no];

所以，最后，你的课程看起来像这样：

public class Gerbil 
{
    private static Gerbil[] gerbils;

    public static void main(String[] args) {

        // write code here to read the array size into gerbil_no

        // then initialize your array with size here
        gerbils =  = new Gerbil[gerbil_no];

        for (int x = 0; x < gerbils.length; x++) {
            gerbils[x] = new Gerbil(types);
        }
        // continue with your code
    }
}

注意：在Java中，静态函数只能访问静态成员。由于main函数（在Java中）是静态的，因此必须将数组声明为static。您可以在此处详细了解：http://www.javatpoint.com/static-keyword-in-java

Answer 2

在你的主要课程中：

private static Gerbil[] gerbils;

public static void main(String[] args) {
    // initializing the Food class into the Gerbil Class
    gerbils =  = new Gerbil[gerbil_no];

    for (int x = 0; x < gerbils.length; x++) {
        gerbils[x] = new Gerbil(types);
    }
}

因为你在静态main函数中使用变量，所以你必须在变量声明中使用static modifier。

Answer 3

把它放在另一个班级：

class Gerbil {
    String lab_id;
    String name;
    boolean isBite;
    public int[] eat;

    public Gerbil(int x) {
        eat = new int[x];
    }

    public String getLab_id() {
        return lab_id;
    }

    public void setLab_id(String lab_id) {
        this.lab_id = lab_id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public boolean isBite() {
        return isBite;
    }

    public void setBite(boolean isBite) {
        this.isBite = isBite;
    }

    public void setEat(int a, int b) {
        eat[a]=b;
    }

    public int getEat(int a){
        return eat[a];
    }
}

class Y {
     private static final int gerbil_no = 0;
     Gerbil[] gerbils = new Gerbil[gerbil_no];
    void foo() {
        // initializing the Food class into the Gerbil Class
        for (int x = 0; x < gerbils.length; x++) {
            gerbils[x] = new Gerbil(10  /* You had types here */);
            gerbils[x].setName("Hello");
        }
    }
    Boolean search (String str) {
        for (int i = 0, length = gerbils.length; i < length; i++)
            if (gerbils[i].name.compareTo(str) == 0)
                return true; 
        return false;
    }
}

使用一个参数-Java搜索数组

3 个答案: