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comp.lang.ruby

operator |=

Chinna Karuppan

2/29/2008 10:15:00 PM

Hi,
I am trying to under this operator |=.Has anybody got some documentation
/ online link to explain this....




THnks
Chinna
--
Posted via http://www.ruby-....
4 Answers

Rob Biedenharn

2/29/2008 10:26:00 PM

0

On Feb 29, 2008, at 5:15 PM, Chinna Karuppan wrote:

> Hi,
> I am trying to under this operator |=.Has anybody got some
> documentation
> / online link to explain this....
>
> THnks
> Chinna


That's one of the assignment operators:

a |= b

is the same as

a = a | b

with all the regular message sending semantics. Look for the | method
of the class of a.

-Rob

Rob Biedenharn http://agileconsult...
Rob@AgileConsultingLLC.com

Paul McMahon

2/29/2008 10:55:00 PM

0

x |=3D y is equivalent to x =3D x | y

7stud --

2/29/2008 11:26:00 PM

0

Chinna Karuppan wrote:
> Hi,
> I am trying to under this operator |=.Has anybody got some documentation
> / online link to explain this....
>
>
>
>
> THnks
> Chinna

The number 10 written in binary format is:

8's 4's 2's 1's
--- --- --- ---
1 0 1 0


The number 11 written in binary format is:

8's 4's 2's 1's
--- --- --- ---
1 0 1 1


Assume 1 is equal to true and 0 is equal to false. Now OR each column
together:

1 0 1 0
1 0 1 1 OR
----------
<--result?

In the first column(the leftmost column) you have (true OR true), which
is true, i.e you write 1 for the result:

1 0 1 0
1 0 1 1 OR
----------
1 <--result?

In the second column, you have (false OR false), which is false, i.e you
write a 0 for the result:

1 0 1 0
1 0 1 1 OR
----------
1 0 <--result?

In the third column, you have (true OR true), which is true:


1 0 1 0
1 0 1 1 OR
----------
1 0 1 <--result?

In the last column, you have (false OR true) which is true:

1 0 1 0
1 0 1 1 OR
----------
1 0 1 1 <--result?

What number is that?

8's 4's 2's 1's
--- --- --- ---
1 0 1 1


1x8 + 0x4 + 1x2 + 1x1 = 11. So 10 | 11 is equal to 11.

The syntax a |= b is similar to the syntax a += 1. a += 1 is equivalent
to a = a + 1. So a |= b is equivalent to a = a | b. From the above you
should now know how to OR two numbers together: convert the numbers to
binary format and then OR the columns together.

--
Posted via http://www.ruby-....

Paul McMahon

2/29/2008 11:59:00 PM

0

On Sat, 01 Mar 2008 08:26:21 +0900, 7stud -- <bbxx789_05ss@yahoo.com>
wrote:

> From the above you
> should now know how to OR two numbers together: convert the numbers to
> binary format and then OR the columns together.
>

Note that in ruby | is just a method. For integers it gives the result of
bitwise or, but other classes define it differently. For instance, Array
defines it to return set union, so [1] | [2] is [1,2].