MASK( ) function

Performs a bitwise AND operation on the first bytes of two character strings.

Syntax

MASK(character_value, character_mask)

Parameters

Name	Type	Description
character_value	character	The string with the byte to test.
character_mask	character	The string with the byte to test against (the mask value).

Output

Character. The output is the character representation of the binary result of the bitwise AND operation.

Examples

Basic examples

Returns "2" (00110010), the result of a bitwise AND of 3 (00110011) and 6 (00110110):

MASK("3", "6")

Remarks

When to use MASK( )

Use MASK( ) to identify specific bit patterns in a byte of data, including whether or not a particular bit is set to 1.

How it works

The MASK( ) function performs a bitwise AND operation on the binary representations of the first characters of character_value and character_mask. The two comparison bytes are compared one bit at a time, resulting in a third binary value.

The result of each comparison of corresponding bits is either 1 or 0:

character_value bit	character_mask bit	Result
0	0	0
0	1	0
1	0	0
1	1	1

Comparison strings longer than one byte

If either comparison string is longer than one byte, subsequent characters are ignored.