Go Premium for a chance to win a PS4. Enter to Win

x
?
Solved

Length

Posted on 2003-11-19
9
Medium Priority
?
257 Views
Last Modified: 2010-03-31
hey,

i'ver develop a programme using a while and for loop to diplay in a table the results of 2^n where 1<=n<64.

However i don't know how to modify the loop to limit the resuts to 10 digits. Also i wish to right align the numbers displayed in the n column.

If anyone knows how to do this, please let me know. If ye want to jazz up the presentation too fire away! thanks!

Here is my code:

/*Computes 2^n where 1<=n<64 and displays in a table*/

class Numbers
{
      public static void main(String[] args)
      {
            byte n = 1;      //declare n, the power, as a byte. initialised at 1 and will not excced 64
            double answer;      //solution of 2^n

            System.out.println("n \t2^n"); //print header of table output

            while (n<64) //iterate loop while n is less than 64
            {
                  answer = Math.pow(2,n); // set answer to 2^n
                  System.out.println(n + "\t" + answer); //print answer
                  n++; //increment n by 1
            } // end of while loop
            

            /*for (n=1; n<64; n++)
            {
                  answer = Math.pow(2,n); // set answer to 2^n
                  System.out.println(n + "\t" + answer); //print answer
                  n=n++; //increment n by 1
            }//end of for loop*/

            
      }//end of main
}//end of class



Thanks as ever

Dinny
0
Comment
Question by:dirtydinny
  • 4
  • 3
  • 2
9 Comments
 
LVL 35

Accepted Solution

by:
TimYates earned 200 total points
ID: 9779140
something like:

-----------

import java.text.* ;

class Numbers
{
  public static void main( String[] args )
  {
    byte n = 1 ; //declare n, the power, as a byte. initialised at 1 and will not excced 64
    double answer ; //solution of 2^n

    DecimalFormat df = new DecimalFormat( "0.##########E00" ) ;
    System.out.println( "n \t2^n" ) ; //print header of table output

    while( n < 64 ) //iterate loop while n is less than 64
    {
      answer = Math.pow( 2, n ) ; // set answer to 2^n
      String sAnswer = df.format( answer ) ;
      while( sAnswer.length() < 15 )
        sAnswer = " " + sAnswer ;
      System.out.println( n + "\t" + sAnswer ) ; //print answer
      n++ ; //increment n by 1
    } // end of while loop

    /*for (n=1; n<64; n++)
               {
         answer = Math.pow(2,n); // set answer to 2^n
         System.out.println(n + "\t" + answer); //print answer
         n=n++; //increment n by 1
               }//end of for loop*/

  } //end of main
} //end of class
0
 
LVL 35

Expert Comment

by:TimYates
ID: 9779260
Hope this is sort of what you wanted...

btw, the DecimalFormat bit limits it to 10 decimal places, and the while loop pads the strings out to a max of 15 chars :-)

Tim
0
 
LVL 86

Expert Comment

by:CEHJ
ID: 9779600
You'll get better output with a BigInteger:

import java.text.* ;
import java.math.BigInteger;

class Numbers
{
      public static void main( String[] args )
      {
            BigInteger bi = new BigInteger("2");
            System.out.println( "n \t\t\t2^n" ) ; //print header of table output
            System.out.println("---------------------------");
            for(int i = 1;i < 64;i++) {
                  String current = bi.pow(i).toString();
                  while(current.length() < 19)
                        current = " " + current;
                  System.out.println(i + "\t" + current);

            }
      } //end of main
} //end of class
0
What does it mean to be "Always On"?

Is your cloud always on? With an Always On cloud you won't have to worry about downtime for maintenance or software application code updates, ensuring that your bottom line isn't affected.

 
LVL 35

Expert Comment

by:TimYates
ID: 9779644
you and your BigIntegers ;-)
0
 
LVL 86

Expert Comment

by:CEHJ
ID: 9779948
Yes, maybe i should create a subclass called 'BigPal' - i'm surprised it isn't final
0
 
LVL 35

Expert Comment

by:TimYates
ID: 9780028
Ooooh...me too >_<
0
 
LVL 92

Expert Comment

by:objects
ID: 9782141
long answer = 0;
for (byte n=1; n<64 && (answer=(long) Math.pow(2, n))<10000000000L; n++)
{
0
 
LVL 92

Expert Comment

by:objects
ID: 9782226
This'll right align your numbers:

StringBuffer out = new StringBuffer();
out.setLength(10 - s.length());
out.append(s);

I'd also suggest not using tabs to align your table and instead add the number of spaces you require.
0
 
LVL 92

Expert Comment

by:objects
ID: 9782450
public static void main(String[] args)
{
   long answer = 0;
   for (byte n=1; n<64 && (answer=(long) Math.pow(2, n))<10000000000L; n++)
   {
      rightAlignValue(n, 2);
      rightAlignValue(answer, 15);
      System.out.println();
   }
}
      
private static void rightAlignValue(long value, int len)
{
   String s = Long.toString(value);
   StringBuffer out = new StringBuffer();
   out.setLength(len - s.length());
   out.append(s);
   System.out.print(out);
}
0

Featured Post

Concerto's Cloud Advisory Services

Want to avoid the missteps to gaining all the benefits of the cloud? Learn more about the different assessment options from our Cloud Advisory team.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

After being asked a question last year, I went into one of my moods where I did some research and code just for the fun and learning of it all.  Subsequently, from this journey, I put together this article on "Range Searching Using Visual Basic.NET …
In this post we will learn how to connect and configure Android Device (Smartphone etc.) with Android Studio. After that we will run a simple Hello World Program.
Viewers learn about the scanner class in this video and are introduced to receiving user input for their programs. Additionally, objects, conditional statements, and loops are used to help reinforce the concepts. Introduce Scanner class: Importing…
This tutorial covers a step-by-step guide to install VisualVM launcher in eclipse.
Suggested Courses

926 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question