How to check a Bit whether it is 1 or 0 (zero) in an Integer (Bitwise Operations)

Level: Beginner

Knowledge Required:

• Bitwise Operators
• Enum

Description:
We usually get statuses from different resources, which contains one or more statuses together. So we require to check whether a particular Status is set or NOT.

Normally statuses are set using Enum

Example:

Public Enum EnumFontStyle
    Regular = 0
    Bold = 1
    Italic = 2
    Underline = 4
    StrikeThrough = 8
End Enum

Public Sub Test()
    Dim fs As EnumFontStyle
    fs = EnumFontStyle.Bold OR EnumFontStyle.Italic
    If fs And EnumFontStyle.Bold Then
        MsgBox("Font is Bold")
    Else
        MsgBox("Font is NOT Bold")
    End If
End Sub

To understand how it is working,

Suppose we have an integer = 3 => binary = 11, if we perform,

3 AND 2

This is in binary

11 AND 10

       11
AND    10
----------
       10 = 2

Hence bit number 2 is 1, because if we do,

4 AND 2 (binary = 100 AND 10)

       100
AND    010
----------
       000 = 0

This means bit number 2 = 0

See Also:
How to add/remove Attribute from File (Bitwise Operation)
How to Make a Bit Zero in an Integer (Bitwise Operation)

How to add/remove Attribute from File (Bitwise Operation)

This article explains how to add or remove Attributes (Read-only, Hidden, etc.) from a file using Bitwise Operators.

Level: Beginner

Knowledge Required:
Bitwise Operations

Description:
In my previous post:

How to Make a Bit Zero in an Integer (Bitwise Operation)

I explained a technique through which we can make a bit Zero in an Integer. In which we used the XOR bitwise operator. XOR actually reverts the bit i.e. if 0 then makes it 1 and if 1 then makes it 0. Therefore we can use XOR to make the bit 0 (Zero) if we are sure that bit is NOT already zero, otherwise we should use the technique described in this post.

For example, we are going to remove the Read-only Attribute from a file.

Remove Read-only Attribute from File:

Dim f As System.IO.FileInfo
f = New System.IO.FileInfo("C:\ABC.txt")
f.Attributes = f.Attributes And (Not IO.FileAttributes.ReadOnly)

Therefore to make the bit zero from an integer we use code

MainIntVar = MainIntVar AND (NOT IntBitToRemove)

Above code is useful to remove the Attribute (Read-only, Hidden, etc.) from a file. Similarly we can add attributes to file,

Add Read-only Attribute to File:

Dim f As System.IO.FileInfo
f = New System.IO.FileInfo("C:\ABC.txt")
f.Attributes = f.Attributes Or  IO.FileAttributes.ReadOnly

See Also:
How to check a Bit whether it is 1 or 0 (zero) in an Integer (Bitwise Operations)
How to Make a Bit Zero in an Integer (Bitwise Operation)

How to Make a Bit Zero in an Integer (Bitwise Operation)

Level: Intermediate

Knowledge Required:
Bitwise Operations

Description:
Sometimes it is required to make a certain bit Zero in an Integer value. For example,

Dim f As FontStyle
f = FontStyle.Bold Or FontStyle.Italic

So in the above Code we have put Bold and Italic both, now suppose we want to remove the Bold then we will use XOR Bitwise Operator as,

f = f XOR FontStyle.Bold

The Bold bit will be set to zero.

XOR:

0 XOR 0 = 0
0 XOR 1 = 1
1 XOR 0 = 1
1 XOR 1 = 0

Note that XOR is actually reverting the bit i.e. 0 (Zero) to 1 and 1 to 0 (Zero). Therefore use XOR if you are sure that the bit we are going to make 0 (zero) is currently 1, otherwise see the following article.

See Also:
How to check a Bit whether it is 1 or 0 (zero) in an Integer (Bitwise Operations)
How to add/remove Attribute from File (Bitwise Operation)