BITOR

Finds the bitwise ‘OR’ value of two numbers and returns it.

Syntax:

BITOR(numberOne, numberTwo)

numberOne and numberTwo must be a decimal and should be 0 or higher.

Example:

If numberOne contains 1 and numberTwo contains 2:

BITOR(1, 2)

returns 3

numberOne:

numberTwo:

Result:

3

Application:

The BITOR (or bitwise OR) function is a logical operation that compares two numbers at the binary level. For each corresponding bit, if either of the bits is a 1, the resulting bit is a 1. If both bits are 0, the result is 0.

A common application of the BITOR function is in computer networking, specifically for setting and managing permissions or flags. Let's consider a scenario where you are managing user permissions for a network-attached storage (NAS) device.

Each permission can be represented by a unique power of 2, also known as a bit flag. This is because in binary, each power of 2 occupies a unique bit position.

	Permission	Decimal Value	Binary Representation
	A	B	C
1	Read	1	0001
2	Write	2	0010
3	Execute	4	0100
4	Delete	8	1000

Now, let's say we have three users and we want to grant them different combinations of permissions. We can use the BITOR function to combine these permissions into a single number.

User Permissions

User 1 (Alice): Needs Read and Write permissions.
Let's perform the bitwise OR operation:
0001 (Read)
OR
0010 (Write)
-------
0011 (Result)

The decimal value of 0011 is 3. So, Alice's permission value is 3.
- Read = 0001
- Write = 0010
- BITOR(Read, Write) = BITOR(1, 2)

User 2 (Bob): Needs Read and Execute permissions.
Let's perform the bitwise OR operation:
0001 (Read)
OR
0100 (Execute)
-------
0101 (Result)

The decimal value of 0101 is 5. So, Bob's permission value is 5.
- Read = 0001
- Execute = 0100
- BITOR(Read, Execute) = BITOR(1, 4)

User 3 (Charlie): Needs Read, Write, and Delete permissions.
Let's perform the bitwise OR operation in two steps:
Step 1: BITOR(Read, Write)
0001
OR
0010
-------
0011

Step 2: BITOR(Result, Delete)
0011 (Result from Step 1)
OR
1000 (Delete)
-------
1011 (Final Result)

The decimal value of 1011 is 11. So, Charlie's permission value is 11.
- Read = 0001
- Write = 0010
- Delete = 1000
- BITOR(Read, Write, Delete) = BITOR(1, 2, 8)

Summary Table

	User	Permissions Granted	BITOR Calculation	Decimal Value
	A	B	C	D
1	Alice	Read, Write	BITOR(1, 2)	3
2	Bob	Read, Execute	BITOR(1, 4)	5
3	Charlie	Read, Write, Delete	BITOR(BITOR(1, 2), 8)	11

Why is this useful?

This method is incredibly efficient for storing and checking permissions. A single number (e.g., 3, 5, or 11) represents a complex set of permissions. To check if a user has a specific permission, a programmer can use a bitwise AND operation. For example, to check if Charlie has "Delete" permission, you would perform BITAND(11, 8), which would result in 8, proving the permission exists. If a user did not have the permission, the result would be 0. This is a very fast and space-efficient way to manage multiple binary flags in computing.