feat: demonstrate console input using System.in.read() (Demo3)

WHAT:
- Implemented a simple program that reads a single byte from the console
  using `System.in.read()`.
- Casts the byte value to a character and prints it.

HOW IT WORKS:
1. `System.in` is a standard input stream connected to the keyboard.
2. `System.in.read()`:
   - Reads a single byte of input as an `int` (0–255).
   - Returns -1 if the end of the stream is reached.
3. The read byte is cast into a `char` to display the entered character.
4. Exceptions (e.g., I/O errors) are caught using a try-catch block.

KEY POINTS:
- Only reads **one character** at a time (first byte of input).
- If you type a character and press Enter, it captures the ASCII code of
  the first character, while the Enter key may remain in the buffer.
- To read full lines or strings, classes like `BufferedReader` or
  `Scanner` are more practical.

REAL-WORLD USE CASES:
- Learning low-level I/O operations in Java.
- Useful for understanding how streams work before moving to higher-level
  input handling.
- Could be applied in
simple console-based
utilities where
byte-level
input is sufficient.

Signed-off-by: https://github.com/Someshdiwan <[email protected]>

Author: Someshdiwan

Section23JavaIOStreams/DemoCodes/src/Demo3.java

@@ -1,21 +1,20 @@
 import java.io.IOException;
+
 class Demo3 {
-    public static void main(String[] args)
-    {
-        try
-        {
+    public static void main(String[] args) {
+        try {
             int x = System.in.read();
             System.out.println( (char)x);
         }
-        catch (IOException e)
-        {
+        catch (IOException e) {
             System.out.println(e);
         }
     }
 }
+
 /*
 This program reads one character from the keyboard input (System.in.read()) and prints it.
 It captures any input/output exceptions that might occur during reading.
 
 Basically, it waits for you to press a key and then shows that character.
-*/
+*/