Unicode escapes in Java are preprocessed before lexical analysis, they can break comments and inject code!

A.java

/**
 * Description:
 *   You can decode the hidden message by running the program.
 *   Compile and execute: user@host:~$ javac A.java && java A
 * 
 * @author Bipin Jitiya
 * @since 2024-12-17
 */
class A {
    public static void main(String[] args){
        /* comment start
        \u002a\u002f\u0020\u0053\u0079\u0073\u0074\u0065\u006d\u002e\u006f\u0075\u0074\u002e\u0070\u0072\u0069\u006e\u0074\u006c\u006e\u0028\u0022\u0079\u006f\u0075\u0074\u0075\u002e\u0062\u0065\u002f\u0055\u0031\u0063\u004e\u0032\u006f\u0068\u0056\u0070\u0033\u0055\u0022\u0029\u003b\u0020\u002f\u002a
        comment ends */
    }
}