Friday, June 13, 2008

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

Level: Intermediate

Knowledge Required:
Bitwise Operations

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.


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)

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