java - 帮助使用 process 方法查找字符串的长度

Question

这是我的歌曲应用程序

/* 
 *
 */

public class SongApp{
  public static void main(String[] args){
  Song song1 = new Song();
  song1.setsongLine("While my guitar gently weeps.");
  song1.display();
  song1.process();
  Song song2 = new Song();
  song2.setsongLine("Let it be");
  song2.display();
  }
}

这是我的支持类(class)

/* 
 *
 */

public class Song{
  // data field declaration
  private String songLine;


  /*sets the value of the data field songLine to input parameter value*/
  public void setsongLine(String songLine){      
    this.songLine = songLine;   
  } //end method  

 /*returns the value of the data field songLine */
 public String getsongLine(){      
    return songLine;      
 } //end method


  //method called process
  public String process(){
    int stringLength = songLine.length();
  }
  /*displays formatted songLine information to the console window */  
  public void display(){     
   System.out.println(songLine); 
   System.out.println("Length is :" + process());
  }
}

所以我的问题是使用处理方法，我需要打印出 SongLine 的长度，然后生成输出，例如长度为:9。但我的处理方法到目前为止似乎不起作用

Answer 1

您需要从 process() 方法返回一个String。

public static void main(String[] args){
    ...
    System.out.println(song1.process());
    ...
}
public String process(){
    return "Length is " + songLine.length();
}

...或者您可以将其设为无效:

public void process(){
    System.out.println("Length is " + songLine.length());
}