toString方法 [英] toString method

问题描述

我想在 Item 类中添加一个 toString 方法，该类返回该项目的标题。

I want to add a toString method in the Item class that returns the title of the item in there.

我需要确保 DVD 类中的toString方法调用 toString Item 中的方法，以便它可以返回包含标题和导演的字符串。

I have need make sure that the toString method in the DVD class calls the toString method in Item so that it can return a string that contains both the title and the director.

Item 是超类， DVD 是子类。

  public class Item
   {
  private String title;
  private int playingTime;
  private boolean gotIt;
  private String comment;

public Item(String theTitle, int time)
{
    title = theTitle;
    playingTime = time;
    gotIt = false;
    comment = "<no comment>";
}

// Getters and setters omitted

public void print()
{
    System.out.print(title + " (" + playingTime + " mins)");
    if(gotIt) {
        System.out.println("*");
    } else {
        System.out.println();
    }
    System.out.println("    " + comment);
}

}

 public class DVD extends Item 
 {
 private String director;

public DVD(String theTitle, String theDirector, int time)
{
    super(theTitle, time);
    director = theDirector;
}

// Getters and setters omitted

public void print()
{
    System.out.println("    director: " + director);
}

}

推荐答案

项 toString ：

public String toString()
{
  return title;
}

DVD toString ：

public String toString()
{
  return super.toString() + " director: " + director;
}

另外，我不知道你要做什么用这个但我会在这些类中放置那些 print（）方法。

Also, I don't know what you're trying to do with this but I would put those print() methods in these classes.

您最好返回字符串表示并将其打印到其他位置（使用此功能，您可以测试此类而无需模拟 System.out ）

You will be better of returning the string representation and printing it somewhere else (with this you can test this class without mocking System.out)

干杯

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