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I am working my way through Head First Rails, and I keep seeing =>. It's in the routes:
map.connect '/marmots/new', controller=>'marmots', :action=>'new'
It's in rendering partials:
render :partial=>"new_marmot"
It's in options for links:
<%= link_to 'Destroy', marmot, :confirm=>'Are you sure?', :method=>:delete %>
Basically, => seems to mean 'equals,' but if so, why not just use an equals sign? Is it more like 'send to?'
How do you pronounce => and what do you understand it to mean? I can get by without knowing this, but it bugs me.
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The :symbol , is as you mentioned it's an efficient way of representing names and strings; they are literal values. It is initialized and exists only once during the ruby session. It's not a string, since you don't have access to String methods; it's a Symbol. On top of that, it's immutable.
-> == Dash Rocket Used to define a lambda literal in Ruby 1.9.
What's a Symbol in Ruby? A symbol is a unique instance of the Symbol class which is generally used for identifying a specific resource.
There are two main differences between String and Symbol in Ruby. String is mutable and Symbol is not: Because the String is mutable, it can be change in somewhere and can lead to the result is not correct. Symbol is immutable.
I've heard it commonly referred to as a "hash rocket". It is the assignment operator used with hashes in ruby. So if you have a hash and want to assign a value to a key (typically a literal), use
{key1 => value1, key2 => value2}
Rails, and other Ruby code, often pass hashes as parameters to methods to achieve the same effect as named arguments in other languages like Python.
object.method({:param1 => value1, :param2 => value2})
EDIT: When reading, I use "gets" as the verb, eg. param1 gets value1, etc.
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