参与分配与创建方法 [英] Assignment involved with creating methods

问题描述

首先感谢你在看我的问题。我的任务是pretty基本大部分，但我是一个没有经验的程序员。下面是分配的描述：

first of all thank you for looking at my question. My assignment is pretty basic to most but I am an inexperienced programmer. Here is the description of the assignment:

你的目标是写一个类名为Storage，可容纳字符串的集合。它必须实现以下方法：

Your objective is to write a class called Storage that can hold a collection of Strings. It must implement the following methods:

1. 的addItem（String s）将 - 此方法接受一个字符串参数，并返回一个布尔值。参数引用然后将其存储在您选择的结构。如果成功添加了引用该方法返回true。


2. getItems（） - 此方法不带参数，返回一个包含存储在内部结构中的所有字符串数组。返回的数组不能包含任何null元素。


3. isFull（） - 这个方法，如果没有内部存储可返回true，否则为false


4. 的removeItem（String s）将 - 此方法接受一个字符串参数，并返回一个布尔值。该方法必须通过内部存储结构搜索和删除参数引用（如present）。如果引用是成功删除的方法返回true，否则为false。

好的家伙，我做了一些改变，我开始有些code，但它不会正确编译。基于这些方法的描述可有人告诉我什么，我做错了吗？

---

I am completely stumped on most of these. I am using an array to store the data, but I am open to other suggestions. Thanks again.

Alright guys I made a few changes and I started some code, but it won't compile correctly. Based on the description of the methods can someone tell me what I'm doing wrong?

公共类存储{

//variables
private String[] list;
private int size = 10;
private int index = 0;

public boolean addItem(String s) {
    for (int i = 0; i < list.length; i++) {
        if (!list.equals(null)) {
            list[i] = s;
        }
    }
    return true;
}

public String[] getItems() {
    for (int i = 0; i < list.length; i++) {
        if(!list.equals(null)) {
        System.out.println(list[i]);
        i++;
        }
    }
    return list;
}

public boolean isFull() {
    if (list.length > size) {
        System.out.println("The array is full");
    }
    return true;
}

public boolean removeItem(String s) {
    for (int i = index; i < list.length - 1; i++) {
        list[i] = list[i + 1];
    }
    return true;
}

}

推荐答案

的addItem（String s）将：该方法应该返回一个布尔值，因为您使用的是的ArrayList ，我们可以使用添加（对象o），它返回一个布尔值。

addItem(String s): The method should return a boolean value, since you are using an ArrayList, we can use add(Object o), which returns a boolean.

public boolean addItem(String s) {
    return list.add(s); // I'm assuming that your instance variable is named list
}

getItems（）：使用方法叫做的ArrayList 类的toArray（） ，传递数组类型的参数转换为。

getItems(): Use the method in the ArrayList class called toArray(), passing in an argument of the array type to cast to.

public String[] getItems() {
    return list.toArray(new String[list.size()]);
}

isFull（）：不完全知道你的老师是问什么在这里，作为一个的ArrayList 将自动调整，但你可以只添加一个实例变量到你的类，它包含一个最大尺寸，然后对证像这样...

isFull(): Not exactly sure what your instructor was asking for here, as an ArrayList will automatically resize, but you could just add an instance variable to your class that contains a maximum size and then check against it like so...

public static final int SIZE = 10;
...
public boolean isFull() {
    return list.size() >= SIZE;
}

当然，这意味着将code检查您要添加元素不违反能力。我会在下面的完整的例子表明这一点。

of course, this means adding code to check that the element you're adding doesn't breach capacity. I'll show this in the complete example below.

的removeItem（String s）将：在的ArrayList 删除（）方法code>超载接受对象删除。同样，这种方法也返回一个布尔值。

removeItem(String s): The remove() method in ArrayList is overloaded to accept an object to remove. Likewise, this method also returns a boolean value.

public boolean removeValue(String s) {
    return list.remove(s); // Removes the first occurrence of the string
}

所有的一切，你应该有类似下面的东西...

All in all, you should have something similar to the following...

public class Storage {
    private ArrayList<String> list = new ArrayList<>();
    public static final int SIZE = 10;

    public boolean addItem(String s) {
        if (isFull())
            return false;
        return list.add(s);
    }
    public String[] getItems() {
        return list.toArray(new String[list.size()]);
    }
    public boolean isFull() {
        return list.size() >= SIZE;
    }
    public boolean removeValue(String s) {
        return list.remove(s); // Removes the first occurrence of the string
    }
}

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