Hide Letters in Java

[Guest_imported]

Can anyone explain how to hide letters in java ?
For example, if I want to make the word "herbert" appear as _ _ _ _ _ _ _ , how do I do this ?

Thanks for any help.

 

[meadandale]

Hide letters WHERE? On the console, in a GUI? When? Why?

 

[Guest_imported]

I want to take a word from a dictionary, then instead of displaying the actual word, I want to display it in the form _ _ _ on a GUI. So instead of a GUI with "The word is : herbert", my GUI should display "Thw word is : _ _ _ _ _ _ _".

I know theres a way to draw the lines in on the GUI, but I'm sure theres a simpler way.

Help!

 

[meadandale]

In reality, you can just do this:

String test = "herbert";
int length = test.length();
char [] echochars = new char[length];
static final char ECHO_CHAR = '_';

for (int i = 0; i < length; i++)
echochars = ECHO_CHAR;

String test2 = new String(echochars);
System.out.println(test2);

There is also the notion of an 'echo character' that is used in some gui components, e.g. password fields that does just what you are saying.

 

[Guest_imported]

Thanks for your help, but can you please tell me where the
echochars = ECHO_CHAR comes from and how it works exactly ?

Thank you for your help

 

[meadandale]

Aww crud. That's a problem in this forum, it should have said:

echochars = ECHO_CHARS;

The tgml processor recognizes the index as a tag. I forgot to turn it off.

 

[Chrissirhc]

I'm confused. If I get your problem correctly you can write something to count the number of letter in your string e.g herbert is 7 letters. You hold 7 in a variable of type int lets say int numberOfLetters. Then you use a for loop from 0 to numberOfLetters (in this case 7). In this for loop you would be printing the character '_' to whereever you want it to go.

This is similar to meadandale's post. I've not given you a program more just the logic behind what you need to write.

Cheers

Chris

 

[Guest_imported]

Thanks for your help, I just can't get this to work.

I get an error : Illegal start of expression
for the line: static final char ECHO_CHAR = '_';

I've tried it my own way, and using the code in the post above, and it doesn't work. I think its this one line thats stopping it working. Apart from that, the program seems to be ok...I think...

 

[toolkit]

Example code:

import java.util.Arrays;

public class Toolkit {

    static final char MASK = '_';

    public static void main( String[] args ) {
        try {
            String in = args[0];
            int length = in.length();
            char[] mask = new char[ length ];
            Arrays.fill( mask, MASK );
            String out = new String( mask );
            System.out.println( in + " becomes " + out );
        } catch( Exception e ) {
            e.printStackTrace();
        }
    }
}

Cheers, Neil

 

[Guest_imported]

Thanks Neil. I'm determined to get my echo char thing running just now though. It works, to a certain extent. For example, I'm outputting a word to DOS at the moment and want it to appear as - - - -. Basically, I want a - in place of a letter. However, say I wanted to output &quot;herbert&quot; in DOS, now what I get is :

-
--
---
----
-----
------
-------

It's like it does what I want, except on different lines.
Since h is the first letter, it goes on its own line with a &quot;-&quot;. e is the 2nd, so it gets &quot;- -&quot; on a separate line, etc.
I'm gonna put my fist through the screen in a minute....

 

[meadandale]

Ok, this is crazy. This is the simplest program:

import java.io.*;

public class HerbertTest
{
static final char ECHO_CHAR = '-';

public static void main(String args[]) throws Exception
{
BufferedReader in =
new BufferedReader(new InputStreamReader(System.in));

String line = null;
printPrompt();
while ((line = in.readLine()) != null)
{
// Trim whitespace
line = line.trim();

// Get hidden representation
String hidden = getHidden(line);

// Print it out
System.out.println(&quot;Your hidden word is: &quot; + hidden);
printPrompt();
}
}

public static String getHidden(String str)
{
if (str == null || str.length() == 0)
return &quot;&quot;;

int len = str.length();
StringBuffer buf = new StringBuffer();
for (int i = 0; i < len; i++)
buf.append(ECHO_CHAR);

return buf.toString();
}

public static void printPrompt()
{
System.out.print(&quot;Enter a word to echo and press <Enter>:&quot;
System.out.flush();
}

}

I've compiled this and run it and it does exactly what you want to the console.