初始化对象数组成功后应用程序崩溃

Question

我想从字符串数组初始化一个对象数组。

public class Card {
    private String pic;

    public Card(String pic) {
        this.pic = pic;
    }

    public String getPic() {
        return pic;
    }

    public void setPic(String pic) {
        this.pic = pic;
    }

    @Override
    public String toString() {
        return "Card{" +
                "pic='" + pic + '\'' +
                '}';
    }
}

package com.example.memorygame;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.util.Log;
import android.view.View;

public class MainActivity extends AppCompatActivity {
    private void main() {
        String[] pictures = {"crocodile", "duck", "lizard", "mosqitue", "parrot", "zebra"};
        //String[] pictures = {"crocodile", "crocodile", "duck","duck", "lizard","lizard", "mosqitue","mosqitue", "parrot","parrot", "zebra" ,"zebra"};
        Card[] cards = new Card[pictures.length*2];
        Functions functions = new Functions();

        for (int i = 0; i < cards.length*2; i+=2) {
            cards[i] = new Card(pictures[i/2]);
            cards[i + 1] = new Card(pictures[i/2]);
            Log.i("case", cards[i].getPic()+" "+String.valueOf(i));
            Log.i("case", cards[i].getPic()+" "+String.valueOf(i+1));
        }
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        main();
    }
}

2020-05-27 17:36:37.345 358-358/? I/case: crocodile 0
2020-05-27 17:36:37.345 358-358/? I/case: crocodile 1
2020-05-27 17:36:37.345 358-358/? I/case: duck 2
2020-05-27 17:36:37.345 358-358/? I/case: duck 3
2020-05-27 17:36:37.345 358-358/? I/case: lizard 4
2020-05-27 17:36:37.345 358-358/? I/case: lizard 5
2020-05-27 17:36:37.345 358-358/? I/case: mosqitue 6
2020-05-27 17:36:37.345 358-358/? I/case: mosqitue 7
2020-05-27 17:36:37.345 358-358/? I/case: parrot 8
2020-05-27 17:36:37.345 358-358/? I/case: parrot 9
2020-05-27 17:36:37.345 358-358/? I/case: zebra 10
2020-05-27 17:36:37.345 358-358/? I/case: zebra 11

在这些日志之后我没有任何东西，也没有找到应用程序崩溃的任何原因。

Answer 1

您的迭代长度错误，导致IndexOutOfBoundsException，因此应用程序崩溃。

for (int i = 0; i < cards.length; i+=2) {
        cards[i] = new Card(pictures[i/2]);
        cards[i + 1] = new Card(pictures[i/2]);
        Log.i("case", cards[i].getPic()+" "+String.valueOf(i));
        Log.i("case", cards[i+1].getPic()+" "+String.valueOf(i+1));
    }

也是在最后一个日志中。我行，你打印了卡片的值[i]，它给出了相同的值，但错误的是，它只打印了0,2,4,6,8,10的值。它应该打印0,1,2,3,4,5,6,7,8,9,10,11的值。