[Rails] Re: Learning About Symbols

On Friday, July 12, 2013 12:49:11 AM UTC-7, Ruby-Forum.com User wrote:

One reason to use Symbols is that they are immutable. When you're
passing one around as an argument or Hash key, it won't change.
Another is that multiple instances of a Symbol are the same object,
making a smaller memory footprint than Strings.

A string is not a symbol. Some structures will use to_s or to_sym to
allow you to pass either as an argument, but that's not their default
behaviour.

> {'a'=>1,:a=>2}
=> {"a"=>1, :a=>2}

> {'a'=>1,'a'=>2}
=> {"a"=>2}

I know about this behavior, but this doesn't answer the question I posted.

I tested my question above.

I can create a hash in ruby and explicitly give it symbols for keys and it will work.

But when I retrieve a hash from a yml file, I cannot reference the keys as symbols.

Are these true or false?

yaml['config'] == yaml[:config]

yaml['config']['another_setting'] == yaml[:config][:another_setting]

The answer to both is false.

So that said, where/how else can symbols be used outside of being hash keys? Thanks. 

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