<identifier> expected

[Eric Rickshaw]

Hey guys.

I'm new to the saloon. My name is Eric. I was wondering if you guys could help me with a program I've been working on. I had my program working with various strings, but I decided to rework it with array lists. The problem is the 17 or so instances of

matrix.add(poem#);
poem#.add(Author);
poem#.add(Title);

I have gives me an identifier expected error. I tried using the just section of the array lists exactly as it appears below in its own class and it worked so Im guessing where the arraylists are placed below they may be in the wrong section of the code. If someone could give me an idea as where to put my arraylists in the context of my program (that Ive included below) I would greatly appreciate it. Thank you.

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.border.*;
import java.util.Random;
import java.util.ArrayList;

public class SonnetRemove extends JFrame {

	private JTextArea textDisplay;
	private JTextField titleInput,
 					   authorInput;
	private JButton newPoem, submit;

	private JLabel titleLabel, authorLabel, authorResult, titleResult;
	String poetGuess;
    String titleGuess;
	String Poet = "";
    String Title = "";
    boolean choice = true;
    boolean firstPoem = false;
		   ArrayList<ArrayList> matrix = new ArrayList<ArrayList>();
       
       ArrayList<String> poem1 = new ArrayList<String>();
       ArrayList<String> poem2 = new ArrayList<String>(); 
       ArrayList<String> poem3 = new ArrayList<String>(); 
       ArrayList<String> poem4 = new ArrayList<String>(); 
       ArrayList<String> poem5 = new ArrayList<String>(); 
       ArrayList<String> poem6 = new ArrayList<String>(); 
       ArrayList<String> poem7 = new ArrayList<String>(); 
       ArrayList<String> poem8 = new ArrayList<String>(); 
       ArrayList<String> poem9 = new ArrayList<String>(); 
       ArrayList<String> poem10 = new ArrayList<String>(); 
       ArrayList<String> poem11 = new ArrayList<String>(); 
       ArrayList<String> poem12 = new ArrayList<String>();
       ArrayList<String> poem13 = new ArrayList<String>(); 
       ArrayList<String> poem14 = new ArrayList<String>(); 
       ArrayList<String> poem15 = new ArrayList<String>(); 
       ArrayList<String> poem16 = new ArrayList<String>();
       ArrayList<String> poem17 = new ArrayList<String>();
       	   matrix.add(poem1);
	   		poem1.add("John Donne");
	   		poem1.add("Sonnet 7");
	   		
	   matrix.add(poem2);
	   	   	poem2.add("John Donne");
	   		poem2.add("Sonnet 10");
	   		
	   matrix.add(poem3);
	   		poem3.add("John Donne");
	   		poem3.add("Sonnet 14");
	   		
	   matrix.add(poem4);
	   	   	poem4.add("John Donne");
	   		poem4.add("Hymn to God in My Sickness");
	   
	   matrix.add(poem5);
	   	   	poem5.add("Robert Herrick");
	   		poem5.add("Delight in Disorder");
	   
	   matrix.add(poem6);
	   	   	poem6.add("Robert Herrick");
	   		poem6.add("Upon Julia's Clothes");
	   
	   matrix.add(poem7);
	   	   	poem7.add("George Herbert");
	   		poem7.add("The Pulley");
	   
	   matrix.add(poem8);
	   	   	poem8.add("George Herbert");
	   		poem8.add("The Collar");
	   
	   matrix.add(poem9);
	   	   	poem9.add("George Herbert");
	   		poem9.add("Easter Wings");
	   
	   matrix.add(poem10);
	   	   	poem10.add("John Milton");
	   		poem10.add("On His Blindness");
	   		
	   //Should I include Paradise Lost?
	   matrix.add(poem11);
	   	   	poem11.add("John Milton");
	   		poem11.add("Paradise Lost Book 12");
	   
	   matrix.add(poem12);
	   	   	poem12.add("Andrew Marvell");
	   		poem12.add("To His Coy Mistress");
	   
	   matrix.add(poem13);
	   	   	poem13.add("Jonathan swift");
	   		poem13.add("A Description of the Morning");
	   
	   matrix.add(poem14);
	   	   	poem14.add("Alexander Pope");
	   		poem14.add("The Rape of the Lock");
	   
	   matrix.add(poem15);
	   	   	poem15.add("William Blake");
	   		poem15.add("The Lamb");
	   matrix.add(poem16);
	   	   	poem16.add("William Blake");
	   		poem16.add("The Tyger");
	   matrix.add(poem17);
	   	   	poem17.add("William Blake");
	   		poem17.add("The Chimney Sweeper");
	   		
    public SonnetRemove() {
    	createUserInterface();
    }
    
    private void createUserInterface(){ 
    	Container contentPane = getContentPane();
    	contentPane.setLayout( null );

    	textDisplay = new JTextArea("Press 'New Poem' to begin");
    	textDisplay.setBounds(10, 10, 420, 20);
    	textDisplay.setLayout( null );
    	textDisplay.setEditable(false);
    	contentPane.add( textDisplay );
    	
    	titleLabel = new JLabel("Title");
    	titleLabel.setBounds(16, 55, 50, 20);
    	titleLabel.setLayout( null );
    	contentPane.add( titleLabel );
    	
    	titleInput = new JTextField("");
    	titleInput.setBounds(50, 55, 325, 20);
    	titleInput.setLayout( null );
    	contentPane.add( titleInput );
    	
    	titleResult = new JLabel("");
    	titleResult.setBounds(50, 80, 325, 20);
    	titleResult.setLayout( null );
    	contentPane.add( titleResult );
    	
    	authorLabel = new JLabel("Poet");
    	authorLabel.setBounds(16, 110, 50, 20);
    	authorLabel.setLayout( null );
    	contentPane.add( authorLabel );
    	
    	authorInput = new JTextField("");
    	authorInput.setBounds(50, 110, 325, 20);
    	authorInput.setLayout( null );
    	contentPane.add( authorInput );
    	
    	authorResult = new JLabel("");
    	authorResult.setBounds(50, 135, 325, 20);
    	authorResult.setLayout( null );
    	contentPane.add( authorResult );
    	
    	newPoem = new JButton("New Poem");
    	newPoem.setBounds(50, 160, 300, 20);
    	newPoem.setLayout( null );
    	contentPane.add( newPoem );
    	newPoem.addActionListener(
    		new ActionListener(){
    			public void actionPerformed( ActionEvent event){
    				newPoemActionPerformed(event);
    			}
    		}
    		);
    	
    	submit = new JButton("Submit");
    	submit.setBounds(385, 55, 75, 75);
    	submit.setLayout( null );
    	contentPane.add( submit );
    	submit.addActionListener(
    		new ActionListener(){
    			public void actionPerformed( ActionEvent event){
    				submitActionPerformed(event);
    			}
    		}
    		);
     
    	setTitle( "Sonnet Test" );
    	setSize(475, 225);
    	setVisible( true );
    	setResizable( false );
    	

}
private void submitActionPerformed(ActionEvent event){
	String titleInputConvert = (titleInput.getText()).toUpperCase();
	String titleAnswer = Title.toUpperCase();
	String authorInputConvert = (authorInput.getText()).toUpperCase();
	String authorAnswer = Poet.toUpperCase();
	if(firstPoem){
	
	if(titleAnswer.equals(titleInputConvert)){
		titleResult.setText("Correct!");
	}
	else{
		titleResult.setText("Incorrect, the title is " + Title);
	}
	
	if(authorAnswer.equals(authorInputConvert)){
		authorResult.setText("Correct!");
	}
	else{
		authorResult.setText("Incorrect, " + Poet + " wrote this poem.");
	}
	
}
}
private void newPoemActionPerformed(ActionEvent event){
authorResult.setText("");
titleResult.setText("");
firstPoem = true;
      int row = generator.nextInt(matrix.size());
      int col = 2+ generator.nextInt((matrix.get(row)).size());
      Poet = (matrix.get(row)).get(0);
      Title = (matrix.get(row)).get(1);
      textDisplay.setText(matrix.get(row)).get(col);
                    
                   
                    
                    
}

public static void main( String[] args){
	   SonnetRemove application = new SonnetRemove();
	   application.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
       
        


}
}

[pete stein]

Eric Rickshaw wrote:so Im guessing where the arraylists are placed below they may be in the wrong section of the code.

It appears to me to be a simple case of trying to call methods outside of a method, constructor, static or initializer block. You can't call code like this:

matrix.add(poem8);

in the class outside of a method, constructor, etc. This is just basic Java, is all.

Edit: there's more involved here. I agree with your use of ArrayList here but don't agree with how you are attempting to implement it as you appear to be trying to create a separate ArrayList for each poem. If it were my app, I'd create a class to hold Poem information, say called "Poem", that would hold a String for the author, a String for the title, and a String for the text of the poem. It would have the typical getter methods. I'd then create one and only one arraylist of Poem that would hold all of the poems: ArrayList<Poem>. YMMV.

[Eric Rickshaw]

Hey pete,

Thanks for your help. Yeah I'm wondering how to position the arraylists. I can see why you would think it might be useful to use strings but I will be adding to each arraylist the lines of each poem. Each line will be in a seperate parrt of the array list. I will generate two random numbers. One will say which of the poems in the big array list is to be selected and then another to generate a random line based on the length of the poem. The line of poetry is displayed in a GUI and the expected values for that poem (title and author) will be set to two variables based on the first and second component of the arraylist for each poem. My intention is two remove a line of poetry from the arraaylist if it is guessed correctly. The code that worked was as followed. Thank you.

 
import java.util.ArrayList;
import java.util.Random;

public class TestAList {

    public static void main(String[] args) {
       ArrayList<ArrayList> matrix = new ArrayList<ArrayList>();
       
       ArrayList<String> poem1 = new ArrayList<String>();
       ArrayList<String> poem2 = new ArrayList<String>(); 
       ArrayList<String> poem3 = new ArrayList<String>(); 
       ArrayList<String> poem4 = new ArrayList<String>(); 
       ArrayList<String> poem5 = new ArrayList<String>(); 
       ArrayList<String> poem6 = new ArrayList<String>(); 
       ArrayList<String> poem7 = new ArrayList<String>(); 
       ArrayList<String> poem8 = new ArrayList<String>(); 
       ArrayList<String> poem9 = new ArrayList<String>(); 
       ArrayList<String> poem10 = new ArrayList<String>(); 
       ArrayList<String> poem11 = new ArrayList<String>(); 
       ArrayList<String> poem12 = new ArrayList<String>();
       ArrayList<String> poem13 = new ArrayList<String>(); 
       ArrayList<String> poem14 = new ArrayList<String>(); 
       ArrayList<String> poem15 = new ArrayList<String>(); 
       ArrayList<String> poem16 = new ArrayList<String>();
       ArrayList<String> poem17 = new ArrayList<String>();
       
       Random generator = new Random();
  
	   matrix.add(poem1);
	   		poem1.add("John Donne");
	   		poem1.add("Sonnet 7");
	   		
	   matrix.add(poem2);
	   	   	poem2.add("John Donne");
	   		poem2.add("Sonnet 10");
	   		
	   matrix.add(poem3);
	   		poem3.add("John Donne");
	   		poem3.add("Sonnet 14");
	   		
	   matrix.add(poem4);
	   	   	poem4.add("John Donne");
	   		poem4.add("Hymn to God in My Sickness");
	   
	   matrix.add(poem5);
	   	   	poem5.add("Robert Herrick");
	   		poem5.add("Delight in Disorder");
	   
	   matrix.add(poem6);
	   	   	poem6.add("Robert Herrick");
	   		poem6.add("Upon Julia's Clothes");
	   
	   matrix.add(poem7);
	   	   	poem7.add("George Herbert");
	   		poem7.add("The Pulley");
	   
	   matrix.add(poem8);
	   	   	poem8.add("George Herbert");
	   		poem8.add("The Collar");
	   
	   matrix.add(poem9);
	   	   	poem9.add("George Herbert");
	   		poem9.add("Easter Wings");
	   
	   matrix.add(poem10);
	   	   	poem10.add("John Milton");
	   		poem10.add("On His Blindness");
	   		
	   //Should I include Paradise Lost?
	   matrix.add(poem11);
	   	   	poem11.add("John Milton");
	   		poem11.add("Paradise Lost Book 12");
	   
	   matrix.add(poem12);
	   	   	poem12.add("Andrew Marvell");
	   		poem12.add("To His Coy Mistress");
	   
	   matrix.add(poem13);
	   	   	poem13.add("Jonathan swift");
	   		poem13.add("A Description of the Morning");
	   
	   matrix.add(poem14);
	   	   	poem14.add("Alexander Pope");
	   		poem14.add("The Rape of the Lock");
	   
	   matrix.add(poem15);
	   	   	poem15.add("William Blake");
	   		poem15.add("The Lamb");
	   matrix.add(poem16);
	   	   	poem16.add("William Blake");
	   		poem16.add("The Tyger");
	   matrix.add(poem17);
	   	   	poem17.add("William Blake");
	   		poem17.add("The Chimney Sweeper");
	   
	  // System.out.println(poem1.get(0));
	  // poem1.remove(0);
      // System.out.println(poem1.get(0))
     
      while(matrix.isEmpty()== false){
      int row = generator.nextInt(matrix.size());
      int col = generator.nextInt((matrix.get(row)).size());
      System.out.println((matrix.get(row)).get(col));
      (matrix.get(row)).remove(col);
      if((matrix.get(row)).size()== 0){
      	matrix.remove(row);
      }
      if(matrix.isEmpty()){
      	break;
      }
      }
      }
    }  
    
    
   

[pete stein]

I still strongly suggest that you create a Poem class and use only one ArrayList<Poem>. A big confusion that new programmers make is to confuse data with code. Your data is the poem information, currently showing title and author. You want the data to be changeable, flexible, alterable, and you want the code to be able to manipulate the data as needed. Right now you are hard-coding your data each into its own tiny arraylist, and when you do this, your losing information and painting yourself into a corner.

If instead you create a Poem class, each bit of a poem's information goes into its proper variable: the title goes into the title field, the poem's name into the name field, and it's all easily and logically extractable. If you want to add 15 or 100 poem's to the ArrayList, it is easy to do, and the same for deleting them.

[Steve Luke]

pete stein wrote:I still strongly suggest that you create a Poem class and use only one ArrayList<Poem>. A big confusion that new programmers make is to confuse data with code. Your data is the poem information, currently showing title and author. You want the data to be changeable, flexible, alterable, and you want the code to be able to manipulate the data as needed. Right now you are hard-coding your data each into its own tiny arraylist, and when you do this, your losing information and painting yourself into a corner.

If instead you create a Poem class, each bit of a poem's information goes into its proper variable: the title goes into the title field, the poem's name into the name field, and it's all easily and logically extractable. If you want to add 15 or 100 poem's to the ArrayList, it is easy to do, and the same for deleting them.

Not to mention the ability to organize the data in a meaningful way - ie sort by author, or poem name, etc...

A simple Poem class might look something like this:

import java.util.ArrayList;
import java.util.List;

public class Poem {
	private final String name, author;
	private final List<String> lines;
	private final int hashcode;
	
	/**
	 * Generate a new Poem with the name and author provided as parameters.  The
	 * text of the Poem can be provided as a List of lines.  The passed in List
	 * may be null, however, at which case the contents of the Poem will be empty
	 * until lines are added through the addLine() method.
	 * 
	 * @param name Name of the Poem
	 * @param author The Poem's writer
	 * @param lines List of lines in the Poem, or null if the lines will be added later
	 */
	public Poem(String name, String author, List<String> lines)
	{
		this.name = name;
		this.author = author;
		if (lines != null)
		{
			this.lines = lines;
		}
		else
		{
			this.lines = new ArrayList<String>();
		}
		
		hashcode = 31 + (7 * this.author.hashCode()) + (7 * this.name.hashCode());
	}

	public String getName() {
		return name;
	}

	public String getAuthor() {
		return author;
	}

	/**
	 * Retrieves a complete list of the textual lines in the poem.
	 * @return a copy of the text of the poem.
	 */
	public List<String> getLines() {
		//defensive copy to prevent an external source from modifying the poem's content
		return new ArrayList<String>(lines);
	}
	
	/**
	 * Append a new line of text to the end of this Poem.
	 * @param line The text of a line to add to the Poem.
	 */
	public void addLine(String line)
	{
		this.lines.add(line);
	}
	
	/**
	 * Get the total count of lines currently in the Poem.
	 * @return
	 */
	public int getLineCount()
	{
		return this.lines.size();
	}
	
	/**
	 * Get a particular line of text from the Poem.
	 * @param lineNumber the line in the Poem to retrieve
	 * @return
	 */
	public String getLine(int lineNumber)
	{
		if (lineNumber >= 0 && lineNumber < this.getLineCount())
		{
			return this.lines.get(lineNumber);
		}
		else
		{
			throw new IllegalArgumentException(String.format("The poem %s does ot have a line number %d.", this.name, lineNumber));
		}
	}
	
	public String toString()
	{
		return String.format("\"%s\", by %s (%d lines)", this.name, this.author, this.getLineCount());
	}
	
	/**
	 * Compare this Poem to a passed in object for equality.  Returns true if this Poem
	 * and the one passed in have the same name and are written by the same author, otherwise
	 * it returns false.
	 */
	@Override
	public boolean equals(Object other)
	{
		if (!(other instanceof Poem))
		{
			return false;
		}
		
		Poem otherPoem = (Poem)other;
		return (this.name.equals(otherPoem.name) && this.author.equals(otherPoem.author));
	}

	@Override
	public int hashCode()
	{
		return hashcode;
	}
}

This would help organize your data, sort, get a particular line you want from the poem, etc...

[Campbell Ritchie]

Steve Luke has given some useful advice; I would simply add a warning against writing == true or == false. You can get nasty errors if you write = instead of == by mistake.
Don't write if (something() == false) . . .
Write if (!something()) . . .

Similarly don't write if (myBoolean == false) . . .
Write if (!myBoolean) . . .

[Eric Rickshaw]

Thank you guys,

I apprciate everybody's help. Thanks for making me feel welcome.