Difference between :symbol => versus symbol:

Question

Possible Duplicate:
Is there any difference between :key => "value" and key: "value" assignments?
key in ruby new hash

I am reading some rails code and I see a method can be called

foo(:var1 => 'hello', :var2 => 'world')

or

foo(var1: 'hello', var2: 'world')

Both seems to work exactly the same. Is there any difference? Which is the better practice?

Thanks for the duplicate comments. I tried searching but I'm not sure how to search when there are symbols like : and => involved — Kirk, Jul 20 '12 at 22:23

score 3 · Accepted Answer · answered Jul 20 '12 at 21:38

3

They mean the same thing. The latter is new Ruby 1.9 syntax inspired by JavaScript. Use the former if you need to stay compatible with Ruby 1.8. Otherwise it's a matter of taste.

answered Jul 20 '12 at 21:38

mpartel

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Iago Moreira · Answer 2 · 2012-08-01T13:32:33.547

0

In a method call, both work exactly the same, but when you make a hash, they will have diferences

# in a method call
foo( :param => 'p' )
# mean the same thing
foo( param: 'p' )

# but in a Hash construction, they will have diferences

# here the key will always be a Symbol
hash = { symb: value }
# but here the key can be anything
hash = { 1 => "1" }
hash = { "1" => 1 }

edited Aug 01 '12 at 13:32

answered Jul 21 '12 at 02:29

Iago Moreira

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4

Uh, what? There's no difference in a method call containing a hash vs. a normal hash construction. – Andrew Marshall Jul 21 '12 at 03:33
You're right, and I'm saying this in the answer. @AndrewMarshall . – Iago Moreira Jul 29 '12 at 15:56
No, you're not. You say, "when you make a hash, they will have diferences" (sic), which is not true. You say this right after saying there are not difference in a method call. – Andrew Marshall Jul 29 '12 at 16:17
You see the code example? And don't understand my explain? @AndrewMarshall – Iago Moreira Jul 31 '12 at 14:06
Your code example includes no method calls, but your text explanation talks about them, so the code you give wouldn't change it. – Andrew Marshall Aug 01 '12 at 11:04

Difference between :symbol => versus symbol:

2 Answers2