将新元素添加到数组时，java.lang.ArrayIndexOutOfBoundsException？ [英] java.lang.ArrayIndexOutOfBoundsException when adding new elements to an array?

问题描述

我有以下 Java 类，它将Person对象添加到现有Person Array ：

I have the following Java class that adds a Person object to an existing Person Array:

 public class PersonService{

 protected int lastItemInPersonArray = 0;

 private Person[] persons = new Person[100];


 public void addPersonToPersonArray(Person personToAdd){

        persons[lastItemInPersonArray++] = personToAdd;

    }

}

我可以添加1对象在这里正确，但当我尝试2我得到以下错误：

I can add 1 object correctly here but when I try to 2 I get the following error:

java.lang.ArrayIndexOutOfBoundsException: 1

导致这种情况的逻辑错误是什么？

What is incorrect with my logic that is causing this?

推荐答案

这对我有用。

public class PersonService {
    protected int lastItemInPersonArray = 0;
    private Person[] persons = new Person[100];
    public void addPersonToPersonArray(Person personToAdd) {
        persons[lastItemInPersonArray++] = personToAdd;
    }   
    public static void main(String[] args) {
        PersonService ps = new PersonService();
        ps.addPersonToPersonArray(new Person("P 1"));
        ps.addPersonToPersonArray(new Person("P 2"));
        ps.addPersonToPersonArray(new Person("P 3"));   
        System.out.println(ps.persons[0].nome);
        System.out.println(ps.persons[1].nome);
        System.out.println(ps.persons[2].nome);
    }
}
class Person{
    public Person(String nome) {
        this.nome = nome;
    }
    String nome;
}

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