strings :: string methods

    // Strings are declared with statements such as:
    String myName = "Eve";
    String newName = new String ("Eve"); //create an object
    // Breaking Strings Apart
    // first position starts at 0 so last character will be in 
    // position length - 1.
    String obj1 = "agnes";

    //length() assigns the # of characters of obj1 to an int variable
    int obj1Length = obj1.length ();
    System.out.println (obj1.length ()); 
    String word = "computer";
    int w1 = word.length (); //returns integer 8
    System.out.println (w1);
    String w2 = word.substring (5);//character 5 to the end of word.
    System.out.println (w2);
    String w3 = word.substring (4, 7);//characters 4, 5 and 6
    System.out.println (w3);
    /* Joining or Concatenating Strings
     If word1 = "word" and word2 = "processing" and word3 = word1 + word2;
     then word3 is "wordprocessing", the strings are joined together
     in the order specified with no space between then */
    String obj2 = "Real ";
    String obj3 = "Madrid";
    String obj4 = obj2 + obj3;
    String obj5= "FC ";
    String club = obj5.concat (obj4);
    System.out.println (club);
    the method replace would replace all occurrences 
    of the first character by the second */
    String obj6 = "oregano";
    String obj7 = obj6.replace ('o', 'a');
    System.out.println (obj7); 
    String word7 = "Computer World";
    String word8 = word7.toUpperCase ();// "COMPUTER WORLD"
    word7 = word8.toLowerCase ();// "computer world" 
    //Searching for Characters and String within Strings
    String obj8= "Karolina";
    int position = obj1.indexOf ("oli"); 
    System.out.println (position);
    // returns 3, the location of the o in karolina
    int position2 = obj1.indexOf ((int) 'l');// karolina
    System.out.println (position2);
   /* Note that the cast integer (int) must be used with a single character.
     to cast is to force a conversion from one data type to another
     The charAt() method will return the character in the position specified.
     Make sure to declare the variable as a 'char' */
    String student = "Marcel";
    for (int i = 0 ; i < student.length () ; i++)
      System.out.println (student.charAt (i));
    char position5 = student.charAt (4); 
    System.out.println (position5 ); // e

    int position6 = student.charAt (4);
    System.out.println (position6); // 101
    String s1 = "yes";
    String s3= new String ("yes");
    if (s1==s3) // not a reference to the same object
    //reference to the same object
    String s2 = s3; 
    if (s2==s3)