feat: Use indexOf with starting index to locate substring in Java String

🔍 Functionality:
- Finds the index of the substring `"udemy"` within `"www.udemy.com"` starting from index `4`.
- Expected output: `4`, since `"udemy"` starts at position 4 in the string.

🧰 Method Used:
- `String.indexOf(String str, int fromIndex)` — searches for the substring starting from the specified index and returns its first occurrence position.

✅ Purpose:
To demonstrate how `indexOf()` can search from a specific position within a string.

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

Author: Someshdiwan

Section6StringClassPrinting/src/StringAB4.java

@@ -1,8 +1,7 @@
 public class StringAB4 {
-    public static void main(String[] args)
-    {
+    public static void main(String[] args) {
         String str1 = "www.udemy.com";
 
         System.out.println(str1.indexOf("udemy", 4));
     }
-}
+}