import java.util.Scanner;

/**
Some more examples for String processing.
*/
public class StringModified
{
  /** These methods return a copy of the string that is modified.
    * concat
    * replace -- replace a character with another character
    * trim -- gets rid of whitespace in the beg and end of string
    * substring (returns a part of the string.) 
    * NONE OF THESE METHODS ACTUALLY MODIFY THE STRING THAT THEY
    ARE CALLED ON SINCE STRINGS IN JAVA ARE IMMUTABLE (NONCHANGEABLE) */
   public static void main(String[] args)
   {
      String doc="Four score and seven years ago"; 
      String sub=doc.substring(5,10);
      System.out.println("sub returned from substring is: "+sub);
    //  doc=doc.substring(5,10); //this is legal. We are saying that the
      // reference variable doc should refer to a different String object
      //System.out.println("doc is now: "+doc);
      // calling sample final question
      System.out.println("grunf returned: " + grunf("Hello","POPE","Ze"));
      
      Scanner in = new Scanner(System.in);
      String answer;
      System.out.print("do you want to continue?");
      answer = in.nextLine();
      String newans=answer.trim();
      if (newans.charAt(0)=='Y' || newans.charAt(0)=='y')
        System.out.println("continuing...");
     
      if (answer.trim().charAt(0)=='y')
        System.out.println("continuing...");
      
      System.out.println("doc with replaced e is: " +
                         doc.replace('e', '*'));
      
      // concatenating 2 strings means connecting them into one string
      String lastName="Doe";
      String firstName="John";
      String fullName=lastName.concat(firstName);
      // Problem: Given a pattern, you want to test whether this
      // pattern occurs in tandem anywhere in your text
      // example: AAG occurs as AAGAAG
      // Solution 1: you should solve using a loop, finding pattern and checking 
      // if it is followed by another pattern.
      // Solution 2:
      String text="TTAAGAAGCC";
      String pattern="AAG";
      if (text.indexOf(pattern.concat(pattern))!=1)
            System.out.println("tandem repeat found!");
      
      
   }
   /** grunf is a question on the sample final */
   public static String grunf(String s1, String s2, String s3) {
      String s = s1.substring(1,2);
      if (s1.length()>s2.length() && s2.compareTo(s3)<0 && s3.indexOf(s)>0)         
             return s1.substring(0,1) + s2.substring(1);
      else
             return s1.substring(0,1) + s2.substring(0,1) + s1.substring(0,1);
   }
        
}