Selective Copying of Characters

Another possibility is to use the String method equalsIgnoreCase(). But it is probably easiest to ignore case from the start. Here is the method:

class Tester
{
  public boolean test( String trial )
  {
    String lower = trial.toLowerCase();

    StringBuffer azBuffer  = new StringBuffer();

    for ( int j=0; j < _______________________; j++ )
    {
       char c = lower.charAt(j);
       if ( c >= 'a' && c <= 'z' )
         azBuffer.__________( c );
    }
    . . . .

  }
}

public class PalindromeTester
{
  . . . . .
}

We will eventually want use the reverse() method of StringBuffer. But first we need to copy just the characters 'a' through 'z' into azBuffer. Doing this causes the method to ignore spaces and punctuation (as we want).