operator |=

[Fernando Cacciola]

Hi people,

Did I dream about an opeartor |=?

I can't find any reference to it in the online docs, yet I think I've seen
it in some samples.

What does it do?

TIA

 

[Eustáquio 'TaQ' Rangel]

Did I dream about an opeartor |=?

I can't find any reference to it in the online docs, yet I think I've
seen it in some samples.
What does it do?

It sets a value if the variable does not have one, like:
=> :bar

Regards,

--
Eustáquio "TaQ" Rangel
http://eustaquiorangel.com

"Simplicity is the ultimate sophistication."
Leonardo da Vinci

 

[John Joyce]

Hi people,

Did I dream about an opeartor |=?

I can't find any reference to it in the online docs, yet I think
I've seen it in some samples.

What does it do?

TIA

It's not exactly an operator itself, it is syntactic sugar.
You can find it well discussed in the archives.
|= means David A. Black.

 

[mortee]

Hi people,

Did I dream about an opeartor |=?

I can't find any reference to it in the online docs, yet I think I've
seen it in some samples.

What does it do?

I can see it in the pickaxe chm, under The Ruby Language => Expressions
=> Operator Expressions.

I guess it's the same as

leftval = leftval | rightval

that is, binary OR.

mortee

 

[Thomas Wieczorek]

Hi people,

Did I dream about an opeartor |=?

It exists

What does it do?

It works for integers like the binary OR:
foo = 3 | 4 # result: 7
bar = 3
bar |= 4 # result: 7

Did you mean ||=? It is used to set default values if a variable is
not definied yet.
foo = 3
foo ||= 4 # foo doesn't change
baz ||= 4 # baz is 4 if it wasn't defined before

Regards, Thomas

 

[Fernando Cacciola]

You might be thinking about ||=

Ha, ya, that one...

Thank you.

I believe a |= b "ORs" the bits in a and b and assigns them to a

Oh, just like in C.... who would have thought (just kiding

Best

Fernando Cacciola
SciSoft
http://fcacciola.50webs.com

 

[Jimmy Kofler]

operator |=

Posted by Fernando Cacciola (Guest) on 06.11.2007 12:59

Hi people,

Did I dream about an opeartor |=?

I can't find any reference to it in the online docs, yet I think I've seen
it in some samples.

What does it do?

|= can also be used with arrays.

shopping_list = ['peanut butter', 'grape jelly', 'whole wheat bread']
shopping_list |= ['peanut butter', 'sugar']
p shopping_list #=> ['peanut butter', 'grape jelly', 'whole wheat
bread', 'sugar']

(cf. http://rubysnips.com/add-to-array-if )

Cheers,

j. k.

 

[Rick DeNatale]

You might be thinking about ||=
||= assigns a value to a variable if the variable is nil

To be precise, it assigns a value to a variable which is either
undefined, nil or false.

 

[Rick DeNatale]

|= means David A. Black.

Hmmmm, I wonder if David knew that! <G>