5 FIVE of the most used bitwise operations

(see the comments in the code):

1. Showing the most right bit (see line #10):

using System;
 
class BitwiseOperations
{
    static void Main()
    {
        int a = 7;
        Console.WriteLine(Convert.ToString(a, 2).PadLeft(32, '0'));//Seeing the number in bits
 
        int result = a & 1;//using & operator
        Console.WriteLine(Convert.ToString(result, 2).PadLeft(32, '0'));//Seeing the most right bit
        Console.WriteLine(result);
    }
}

2. Showing a bit with defined position (see lines #11 and #14):

using System;
 
class BitwiseOperations
{
    static void Main()
    {
        int a = 444;
        Console.WriteLine("The NUMBER: " + Convert.ToString(a, 2).PadLeft(32, '0'));
 
        int p = 2;
        int aRightp = a >> p;//using shift >> operator
        Console.WriteLine("  The MASK: " + Convert.ToString(aRightp, 2).PadLeft(32, '0'));
 
        int result = aRightp & 1;//using & operator + putting 1
        Console.WriteLine("The RESULT: " + Convert.ToString(result, 2).PadLeft(32, '0'));
        Console.WriteLine(result);
    }
}

3. Changing user-defined bit with 1 (see lines #11 and #14):

using System;
 
class BitwiseOperations
{
    static void Main()
    {
        int a = 2;
        Console.WriteLine("The NUMBER: " + Convert.ToString(a, 2).PadLeft(32, '0'));
 
        int p = 2;
        int mask = 1 << p;//SHIFT operator << on left + putting 1
        Console.WriteLine("  The MASK: " + Convert.ToString(mask, 2).PadLeft(32, '0'));
 
        int result = mask | a;//using | operator on the mask and the number
        Console.WriteLine("The RESULT: " + Convert.ToString(result, 2).PadLeft(32, '0'));
        Console.WriteLine(result);
    }
}

4. Changing user-defined bit with 0 (see lines #11 and #14):

using System;
 
class BitwiseOperations
{
    static void Main()
    {
        int a = 6;
        Console.WriteLine("The NUMBER: " + Convert.ToString(a, 2).PadLeft(32, '0'));
 
        int p = 2;
        int mask = ~(1 << p);//(using ~) + (SHIFT on left and putting 1)
        Console.WriteLine("  The MASK: " + Convert.ToString(mask, 2).PadLeft(32, '0'));
 
        int result = mask & a;//using & operator on the mask and the number
        Console.WriteLine("The RESULT: " + Convert.ToString(result, 2).PadLeft(32, '0'));
        Console.WriteLine(result);
    }
}

5. Changing user-defined bit with the opposite bit (see lines #11 and #14):

using System;
 
class BitwiseOperations
{
    static void Main()
    {
        int a = 2;
        Console.WriteLine("The NUMBER: " + Convert.ToString(a, 2).PadLeft(32, '0'));
 
        int p = 2;
        int mask = 1 << p;
        Console.WriteLine("  The MASK: " + Convert.ToString(mask, 2).PadLeft(32, '0'));
 
        int result = mask ^ a;//using ^ operator on the mask and the number
        Console.WriteLine("The RESULT: " + Convert.ToString(result, 2).PadLeft(32, '0'));
        Console.WriteLine(result);
    }
}

3 useful videos to watch about bitwise operators in C#:

Here is one simple hack to check whether a number is EVEN or ODD:

• The number is EVEN if it's youngest bit0 is 0.
• In 0001 0111 - the youngest bit (bit0) is 1 - so it is ODD)

To find it out for sure (and create console application) - we need to use & (AND) operator with 1 which will replace all the other bits except for the youngest one - b0;

If the result of this operation is 0 - the number is EVEN; if it is 1 - it is ODD;

Here is an example to make it clear:

The number 23 - it is ODD:

The binary representation of 23 is 10111 (use Windows Calculator) - as you can see the youngest bit (bit0) - is 1 - so we know that the number is ODD.

In order to write a program we'll need the & operator - and it will look like this:

0001 0111  &
0000 0001   (1 in this case is: 0000 0001)
––––
0000 0001

The code in Visual Studio for C# will look like this:

using System;
 
class Bits
{
    static void Main()
    {
        int number = int.Parse(Console.ReadLine());
        if ((number & 1) == 0)
        {
            Console.WriteLine("The number {0} is EVEN", number);
        }
        else if ((number & 1) != 0) //or ((number & 1) == 1)
        {
            Console.WriteLine("the number {0} is ODD", number);
        }
    }
}