“int 不能被取消引用"；在爪哇 [英] "int cannot be dereferenced" in Java

问题描述

我对 Java 还很陌生，我正在使用 BlueJ.我在尝试编译时不断收到这个Int cannot be dereferenced"错误，我不确定问题是什么.该错误特别发生在我底部的 if 语句中，它说等于"是一个错误，int 不能被取消引用".希望得到一些帮助，因为我不知道该怎么做.提前谢谢！

I'm fairly new to Java and I'm using BlueJ. I keep getting this "Int cannot be dereferenced" error when trying to compile and I'm not sure what the problem is. The error is specifically happening in my if statement at the bottom, where it says "equals" is an error and "int cannot be dereferenced." Hope to get some assistance as I have no idea what to do. Thank you in advance!

public class Catalog {
    private Item[] list;
    private int size;

    // Construct an empty catalog with the specified capacity.
    public Catalog(int max) {
        list = new Item[max];
        size = 0;
    }

    // Insert a new item into the catalog.
    // Throw a CatalogFull exception if the catalog is full.
    public void insert(Item obj) throws CatalogFull {
        if (list.length == size) {
            throw new CatalogFull();
        }
        list[size] = obj;
        ++size;
    }

    // Search the catalog for the item whose item number
    // is the parameter id.  Return the matching object 
    // if the search succeeds.  Throw an ItemNotFound
    // exception if the search fails.
    public Item find(int id) throws ItemNotFound {
        for (int pos = 0; pos < size; ++pos){
            if (id.equals(list[pos].getItemNumber())){ //Getting error on "equals"
                return list[pos];
            }
            else {
                throw new ItemNotFound();
            }
        }
    }
}

推荐答案

id 是原始类型 int 而不是 Object.您不能像在此处那样调用原语上的方法:

id is of primitive type int and not an Object. You cannot call methods on a primitive as you are doing here :

id.equals

尝试替换这个:

        if (id.equals(list[pos].getItemNumber())){ //Getting error on "equals"

与

        if (id == list[pos].getItemNumber()){ //Getting error on "equals"

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