Need Help! Java & TextPad

cyberwit

I keep getting the same error message everytime i compile and try to rum a java program i write even though the same program worked when i ran it in college.

I have installed the compiler J2SE Development Kit 5.0 Update 6
I have installed TextPad
And have my two classes saved in the folder where i save my Java programs

program is as follows

class ex1A{
public static void main(String[]args){

int f[]=new int[5]; //Array
for(int j=0;j<f.length;j=j+1){ //For statement
Screen.message("Enter a number into number"); //Writes message to screen
f[j]=Keyboard.readInt(); //Assigns value from keyboard
Screen.writeInt(f[3]); // Displays whats in variable
}
}
}

I keep getting the following error message

C:\Documents and Settings\user\My Documents\JAVA Semester 2\ex1A.java:6: cannot find symbol
symbol : variable Screen
location: class ex1A
Screen.message("Enter a number into number"); //Writes message to screen
^
C:\Documents and Settings\user\My Documents\JAVA Semester 2\ex1A.java:7: cannot find symbol
symbol : variable Keyboard
location: class ex1A
f[j]=Keyboard.readInt(); //Assigns value from keyboard
^
C:\Documents and Settings\user\My Documents\JAVA Semester 2\ex1A.java:8: cannot find symbol
symbol : variable Screen
location: class ex1A
Screen.writeInt(f[3]); // Displays whats in variable
^
3 errors

Tool completed with exit code 1

Even though i have my Keyboard and screen class setup exactly like in college

themole

cyberwit wrote:

Tool completed with exit code 1

Even though i have my Keyboard and screen class setup exactly like in college

but did you import them?

cyberwit

No
I got them from www.tonymullins.com

pH

If you have the 3 files (Keyboard.java, Screen.java and ex1A.java) in the *same directory* and type:

javac ex1A.java

It will work fine

cyberwit

Keyboard and Screen are classes


I do not use this syntax -System.out.printIn("Hello World!")-; the above Keyboard and Screen allow me to use Screen.message("Hello");
or
Screen.writeInt(x); instead of System.out.printIn( )

from Tony Mullins A first Course in Programming in Java

pH

Still the same thing holds if they are in the same directory (the 2 class files and your java file) it compiles for me.

However check that all files have exactly the right names - capitalisation is important.

If that fails download the 2 java files from the website (Screen & Keyboard) and put them in the dir instead of the classes. The ones you have may have been compiled with a package identifier and won't work just put in the same dir.

rsynnott

cyberwit wrote:

No
I got them from www.tonymullins.com

Gah, there seems to be an epidemic of these sorts of classes in the educational sector. What is wrong with allowing the student to use the language's own I/O classes is beyond me.

pH

rsynnott wrote:

Gah, there seems to be an epidemic of these sorts of classes in the educational sector. What is wrong with allowing the student to use the language's own I/O classes is beyond me.

I agree, a critique of the what the good Mr Mullins is teaching is in order!

From Screen.java on the site

public static void cursorpos(int x){
  int j;
  if(x>0)
    for(j=0;j<x;j++)
      System.out.print(" ");
  else
    ; // skip
  }

How many things are wrong with those lines?

rsynnott

Yargh!!