将多个值保存在数组中的相同索引处

Question

My code retrieves a number of steps, then will output an instruction at each step via for loop. There will be a title, description, video, and audio. However, I am trying to think of a way to store each variable into a structure. This is what I came up with, but I don't think an array can store multiple values at the same index.

for(int i = 0; i < QRData.number_steps; i++){
        System.out.println("Inside for loop");
        array[i].setTitle(btn_instructions.get(i));
        array[i].setDescription(instruction_row.get(i));
        array[i].setInstructionVideo(videos.get(i));
        array[i].setAudioInstruction(audio.get(i));
}

What would be a better way to store these values, so that they are easy to retrieve later? I'm pretty sure my method doesn't work.

Answer 1

You should create a Object like:

public class DataStorage{

  private String title;

  private String description;

  private File audioFile;

  private File videoFile;

  public DataStorage(String title, String description, File audioFile, File videoFile){
    this.title = title;
    this.description = description;
    this.audioFile = audioFile;
    this.videoFile = videoFile;
  }

  public String getTitle(){
    return this.title;
  }
 //similar for "description", "audioFile" and "videoFile"
 //...
}

For the DataStorage i would recommend using a ArrayList, because it is dynamic and you can add new elements while the Programm is running. Then you can save Data in there with the loop:

ArrayList<DataStorage> storage = new ArrayList<>();

for(int i = 0; i < QRData.number_steps; i++){
    storage.add(new DataStorage(btn_instructions.get(i),instruction_row.get(i),
    videos.get(i),audio.get(i));
}

This is a basic concept of object oriented Programming to define classes to store custom data.

You can now get the Data out of the Array by calling the "getters" of your Datastorage class. For example:

String title = storage.get(itemNumber).getTitle();

gives you the value of the "itemNumber" Title.

Answer 2

您应该创建一个新对象来存储这些值，然后将该对象存储在数组中。

Answer 3

You have to use objects arrays, using this you are going to create a class and an array of your class, for example check ne following code:

class Person{
private String name;
private Integer age;

Person(String name,Integer age){
     this.name=name;
     this.age=age;
}
----getters and setters methods-----

}

class Test{
public static void main(String args[]){
Person arr[]=new  Person[10];
arr[0]=new Person("Alex",26);
}
}

Check a complete example here http://www.java2s.com/Tutorial/Java/0200__Generics/ArraysStoringclassobjectsinArrayasdataitems.htm

Cheers