feat: Add TestString class to demonstrate Java String operations

- Introduced `TestString` class to illustrate common String methods and comparisons.
- Used `length()` to get the number of characters in a String.
- Demonstrated `charAt(index)` to access specific characters:
  - Extracted a character from a hardcoded index (`6`) in "Virat Kohli"
  - Used `length - 1` to get the last character of "Ram"
- Compared two strings (`name` and `name1`) using:
  - `equals()` — case-sensitive comparison
  - `equalsIgnoreCase()` — case-insensitive comparison
- Compared `str1 = "remote"` and `str2 = "car"` using `compareTo()` to demonstrate lexicographical comparison based on ASCII values.
- Printed ASCII values of characters 'r' and 'c' using `'char' + 0` trick.

This commit provides a basic reference for String manipulation, comparison, and character operations in Java.

Signed-off-by: Somesh diwan <[email protected]>

Author: Someshdiwan

Section6StringClassPrinting/Engineering Digest ED/src/TestString.java

@@ -26,4 +26,4 @@ public static void main(String[] args) {
         System.out.println('r'+0);
         System.out.println('c'+0); //114-99=15
     }
-}
+}