class StringDemo {
public static void main(String args[]) {

// Four versions that do the same thing.
String myString1 = new String("Hello there"); // Declare and create

String myString2 = "Hello there";             // Declare and create

String myString3;           // Declare
myString3 = "Hello there";  // Create

String myString4;                        // Declare
myString4 = new String("Hello there");   // Create

System.out.println("First string is  - " + myString1);
System.out.println("Second string is - " + myString2);
System.out.println("Third string is  - " + myString3);
System.out.println("Fourth string is - " + myString4);

String david = "David Langan"; // Declare and create.

String davidLangan = null;     // Declare reference and set to null.
// Just had the declaration for davidLangan but have not set it to
// refer to a specific object yet.  We can test to see if it is "null";
if (davidLangan == null)
System.out.println("Yes... the object reference is not set yet.");
else
System.out.println("What?? I got set somehow?");

davidLangan = david;           // Have reference refer
String dL = new String(david); // Create new object
System.out.println("First version is  - " + david);
System.out.println("Second version is - " + davidLangan);
System.out.println("Third version is  - " + dL);

if (david == davidLangan)
System.out.println("david & davidLangan do refer to same object");
else
System.out.println("david & davidLangan do NOT refer to same object");

if (david == dL)
System.out.println("david & dL do refer to same object");
else
System.out.println("david & dL do NOT refer to same object");

dL = "David D. Langan";  // Create new String and have dL refer to it.
// Old "David Langan" object is garbage and
// its space will automatically be reclaimed.
System.out.println("New dl holds : " + dL);

System.out.println("Length of 'Hello there' is : " + 
"Hello there".length());

System.out.println("   Me   trimmed is:" + "   Me   ".trim());
System.out.println("This is a test".substring(2));
System.out.println("This is a test".substring(2,6));

System.out.println("Hello there".charAt(0));
System.out.println("Hello there".charAt(2));
System.out.println("Hello there".charAt(10));

// Try uncommenting the next line to see the error
// that results if you try to execute it.  The Java interpreter (java)
// catches this error and gives you a runtime error message.
// One might have thought that with the 11 sitting right there in the
// code itself that the compiler might have caught this error before
// we even got to runtime, but that was not the case.
// System.out.println("Hello there".charAt(11));

System.out.println("Hello there".replace('e','i'));
System.out.println("This is 4 a TEST".toLowerCase());
System.out.println("This is 4 a TEST".toUpperCase());

String hello1 = new String("Hello");
String hello2 = new String("Hello");
if (hello1 == hello2)
System.out.println("String references are equal.");
else
System.out.println("String references are NOT equal."); // Prints this!

if ( hello1.equals(hello2) )
System.out.println("String contents are equal.");       // Prints this!
else
System.out.println("String contents are NOT equal.");

if ( "Hello There".equalsIgnoreCase("heLLo THEre") )
System.out.println("Yes two versions of hello there were the same.");
else
System.out.println("No, two versions of hello there were NOT " +
" the same.");

if ("This is a test".compareTo("This is b test") < 0)
System.out.println("The 'a' version is less than the 'b' version");
else
System.out.println("The 'a' version is NOT less than the 'b' version");

System.out.println("Hello there".indexOf('H'));
System.out.println("Hello there".indexOf('e'));
System.out.println("Hello there".indexOf('x'));
System.out.println("Hello there".indexOf('H',5));
System.out.println("Hello there".indexOf('t'));
System.out.println("Hello there".indexOf("ll"));
System.out.println("Hello there".indexOf("ll",5));
System.out.println("Hello there".indexOf("he"));

if ( "Hello there".startsWith("He") )
System.out.println("'Hello there' does start with 'He'");
else
System.out.println("'Hello there' does not start with 'He'");

if ( "Hello there".startsWith("Hx") )
System.out.println("'Hello there' does start with 'Hx'");
else
System.out.println("'Hello there' does not start with 'Hx'");

if ( "Hello there".startsWith("ll",2) )
System.out.println("'Hello there' does have an 'll' starting at 2");
else
System.out.println("'Hello there' doesn't have an 'll' starting at 2");

System.out.println(String.valueOf(25)); 
System.out.println(String.valueOf('a'));
System.out.println(String.valueOf(true));
System.out.println(String.valueOf(3.14));

} // End of function main()

}