I WANT2 CHANGE METHOD, BUT IT DOESNT WORK, HELP~

[Jose Cisse]

hello everyone~~~im trying2 creat a program for inventory of bookshop

and i ve made several classes and they r interactive

just wonder: ...

 import java.util.*;
public class bookshop
{
  private KeyboardInput in;
  private inventory inventory;
  private RecordList recordlist;
  public bookshop()
  {
    in = new KeyboardInput();
    inventory = new inventory();
    recordlist = new RecordList();
  }
 
  public void go()
  {
    while (true)
    {
      displayCommands();
      int command = getCommand();
      if (quitSelected(command))
      {
        break;
      }
      runCommand(command);
    }
  }
  private void displayCommands()
  {
    System.out.println("\nWelcome to Book Shop");
    System.out.println("\n********************************");
    System.out.println("1. Display Book List");
    System.out.println("2. Add Book Item");
    System.out.println("3. Remove Book Item");
    System.out.println("4. Change Price of Book Item");
    System.out.println("5. Save This Book");
    System.out.println("6. Load Book");
    System.out.println("7. Enter Record");
    System.out.println("8. Display Record");
    System.out.println("9. Quit");
    System.out.println("\n********************************");
  }
  private int getCommand()
  {
    System.out.print("\n Enter Selection: ");
    return in.readInteger();
  }
  private boolean quitSelected(int n)
  {
    return (n == 9)? true : false;
  }
  private void runCommand(int item)
  {
    switch (item)
    {
      case 1:
        displayinventory();
        break;
... ...   

this iz some method in my main bookshop class, and now i want2 change them2 "things like":

  import java.util.ArrayList;
 
public class bookshop
{
  private static final int DISPLAY B = 1;
  private static final int ADD = 2;
  private static final int REMOVE = 3;
  private static final int CHANGE = 4;
  private static final int SAVE = 5;
  private static final int LOAD = 6;
  private static final int ENTER = 7;
  private static final int DISPLAY R = 8;
  private static final int QUIT = 9;
  private KeyboardInput in = new KeyboardInput();
  private ArrayList inventory = new ArrayList();
  private ArrayList record = new ArrayList();
 
  public void run()
  {
   while(true)
   {
    displaymenu();
    int option = getMenuInput();
    if (option ==QUIT)
    {
     break;
    }
    doOption(option);
   }
  }
 
.........  

i tried it, but it doesnt work~~~iz there anyway2 do it???~~~if i done this, iz there affect2 other classes/the whole thing? OR no more interactive???

THX A LOT~~~~~~~~~~

[marc weber]

When you say it "doesn't work," what exactly do you mean? Are there error messages at compilation? At runtime?

(If you're using Java 5.0, then you should look at the new enums feature.)

[Christophe Verré]

1. Please avoid using capital letters (this is used for shouting)
2. Please avoid use bold characters to focus on something. Do not bold the whole message
3. Please do not use abbrevations like 'r' for 'are', '2' for 'to', or words like 'iz' for 'is'. It just makes it difficult to read for non native speakers.

Thank you

[Jose Cisse]

Originally posted by Satou kurinosuke:
1. Please avoid using capital letters (this is used for shouting)
2. Please avoid use bold characters to focus on something. Do not bold the whole message
3. Please do not use abbrevations like 'r' for 'are', '2' for 'to', or words like 'iz' for 'is'. It just makes it difficult to read for non native speakers.

Thank you

really sorry~~~

[Jose Cisse]

Originally posted by marc weber:
When you say it "doesn't work," what exactly do you mean? Are there error messages at compilation? At runtime?

(If you're using Java 5.0, then you should look at the new enums feature.)

yes, there are error messages coming out
like for "private static final int DISPLAY B = 1;"

"; expected"
... ...

[Christophe Verré]

Your variable must be one word.
Try to change "DISPLAY B" by something like "DISPLAY_B"
Same for "DISPLAY R".

[marc weber]

Originally posted by Jose Cisse:
...yes, there are error messages coming out
like for "private static final int DISPLAY B = 1;"

"; expected"
...

Oh, I see. You can't have a space in an identifier (variable name). You could use underscores, like DISPLAY_B and DISPLAY_R.

[Jose Cisse]

OH~~~got it~~~THX a lot~~~


and...how do i deal with word "menu" ?
it always shows the error message:"cannot resovle symbol"

like: for" int option = getMenuInput();"

the error message coming out" cannot resovle symbol-method getMenuInput()"
???

MANY THX~~~

[Christophe Verré]

It cannot find the method getMenuInput(). Are you sure there is such a method in your class ? If there is, check typos in its name.

[Jose Cisse]

yes, i think so
i worte like

  public void run()
  {
   while(true)
   {
    displaymenu();
    int option = getMenuInput();
    if (option ==QUIT)
    {
     break;
    }
    doOption(option);
   }

but method "displaymenu" cannot resolve sybmol as well...why???

[Christophe Verré]

You are calling methods, but do they actually exist ?
You should have those methods somewhere:
[/code]
void displaymenu() {
...
}
int getMenuInput() {
...
}
void doOption(int) {
...
}
[/code]

[Jose Cisse]

Originally posted by Satou kurinosuke:
You are calling methods, but do they actually exist ?
You should have those methods somewhere:
[/code]
void displaymenu() {
...
}
int getMenuInput() {
...
}
void doOption(int) {
...
}
[/code]

sorry, can you say abit more specific?
if they dont exist, how do i fix them? OR example please~~~

MANY THX~~~

[Christophe Verré]

  public void run()
  {
   while(true)
   {
    displaymenu();   // 1
    int option = getMenuInput();  // 2
    if (option ==QUIT)
    {
     break;
    }
    doOption(option); // 3
   }

1. You are calling displaymenu(). Where is this method ?
2. You are calling getMenuInput(). Where is this method ?
3. You are calling doOption(). Where is this method ?

[Jose Cisse]

ok, i understand it...
but how do you create those method (in order to make the whole thing work)???

MANY THX~~~

[Christophe Verré]

Is this some homework ? I don't want to throw out the solution if you were asked to do this.
But think about it. There were already the necessary methods in the first version of your program. The second version contains the same logic, with different method names.

[Jose Cisse]

Originally posted by Satou kurinosuke:
Is this some homework ? I don't want to throw out the solution if you were asked to do this.
But think about it. There were already the necessary methods in the first version of your program. The second version contains the same logic, with different method names.

ok~~~thx a lot~~~