Just write a Hello World on the next feel a little difficult to absorb the

{class Demo03 public 
    public static void main (String [] args) { 
        // hexadecimal binary expansion of an integer of decimal octal 0b 0 hex 0x 
        int I = 10; 
        int I2 = 010; // octal 0 
        int I3 = 0x11; // hexadecimal 0-9 A-F16 0x 
        System.out.println (I); 
        System.out.println (I2); 
        System.out.println (I3); 
        System.out.println ( "=== ======================================== "); 
        // ===== =============================================== 
        // float points expand? Banking express how? Money 
        // BigDecimal mathematical tools 
        // ========================================= ================ 
        // float finite discrete rounding errors about close to, but not equal to 
        // double
        // best to avoid using the floating-point compare 
        // best to avoid using the floating-point compare 
        // best to avoid using the floating-point compare 


        a float F = 0.1f; //0.1 
        Double D = 1.0 / 10; / /0.1 

        System.out.println (D == F); to false // 
        System.out.println (F); 
        System.out.println (D); 


        a float D1 = 1651321545; 
        a float = D1 + D2. 1; 
        the System.out .println (== D1 D2); // to true 


        // ==================================== ======================== 
        // characters to expand? 
        // ================================================ ============ 
        System.out.println ( "=============================== =========== "); 
        char C1 = 'A'; 
        char C2 = 'and';

        System.out.println (C1); 
        System.out.println ((int) C1); // cast (= 97 A) (A = 65) 
        System.out.println ((C2)); 
        the System.out. println ((int) c2); // cast 
        // essentially all of the characters or numbers 
        // Unicode encoding to start the beginning 2 bytes can represent from 0--16 th power of 2 = 65536 65536 Excel table: (97 A = A 65 =) 
        // u0000 uFFFF 

        char a C3 = '\ u0061'; A // 

        // escape character 
        // \ T tab 
        // \ n-newline 
        //. . . . 

        System.out.println ( "the Hello \ tWorld"); 

        System.out.println ( "============================== =============================== "); 

        // extended Boolean 
        Boolean = In Flag to true; 
        IF (In Flag to true == ) {} // novice
        if (flag) {} // veteran 
        // Less is More! To streamline the code read 

    } 
}