Numeric inputs to OR function

[ajinkya007]

Hello Friends,

I have a question regarding the working of OR function when both it's inputs are numbers. I tried myself and found that, when both my inputs are same, then I get the output as the input value. Ex.  input 1= 10 and input 2=10 then I get answer as 10.

When I give different inputs, then I get the addition of the inputs as the answer. Ex. input 1= 20 and input 2=10 then I get answer as 30.

But when I give higher number as a input, then I get completely different result (which is not the addition of numbers).

Ex. input 1= 1000 and input 2=10 then I get answer as 1002.

Could anyone please explain me how exactly OR function here is computing the output?

Thanks in advance! 🙂

[GerdW]

Hi ajinkya,

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@ajinkya007 wrote:

When I give different inputs, then I get the addition of the inputs as the answer. Ex. input 1= 20 and input 2=10 then I get answer as 30.

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This is only partially correct: OR is considered a "boolean addition"! (AND is the "boolean multiplication"…)

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@ajinkya007 wrote:

But when I give higher number as a input, then I get completely different result (which is not the addition of numbers). Ex. input 1= 1000 and input 2=10 then I get answer as 1002.

Could anyone please explain me how exactly OR function here is computing the output?

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You are working with (hopefully) integer numbers, which consist of several bits (aka booleans). Those bits are ORed…

1000d = 1111101000b
0010d = 0000001010b
   OR = 1111101010b

[crossrulz]

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@ajinkya007 wrote:

Could anyone please explain me how exactly OR function here is computing the output?

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As GerdW already stated, when OR with integers, it is a bit-wise OR.  Similar for AND, XOR, etc.

[altenbach · Accepted solution]

Both AND and OR operate bitwise on integers. (All this is explained in the help) Bitwise operation have nothing to do with addition or multiplication at all..

OR: The new number is an integer where all bit are TRUE where at least one of the inputs has a bit set.

AND: The new number is where only the bits are TRUE that are true in both inputs.

Assuming 16 bit numbers (using one of your examples):

A       = b0000001111101000 (1000 in decimal)

B       = b0000000000000010 (2 in decimal)

A OR B  = b0000001111101010 (1000 OR 2, i.e. 1002 in decimal)

A AND B = b0000000000000000 (1000 AND 2, i.e. 0 in decimal)