CODEWITHSUNDEEP
ruby-on-railsruby
mhaseeb
mhaseeb

Reputation: 1779

Will the try method and the && operator serve the same purpose?

Suppose there is a model user.rb. And I have a method define firstname.

def firstname
 shipping_address.try(:firstname)
end

def firstname
  shipping_address && shipping_address.firstname
end

In both cases we are trying avoid unwanted exceptions. Is that what try is being used for?

Upvotes: 2

Views: 58

Answers (4)

Tobias
Tobias

Reputation: 4653

As @dharam already said, the #try method is a Rails method and && is plain ruby. The source code of it is pretty straightforward. But no they are not the same since as @sawa already said - && the operation cancels if an expression is nil of false.

Here the source code (#try, without bang, uses this method):

def try!(*a, &b)
  if a.empty? && block_given?
    if b.arity == 0
      instance_eval(&b)
    else
      yield self
    end
  else
    public_send(*a, &b)
  end
end

Upvotes: 0

sawa
sawa

Reputation: 168179

No.

&& cancels further application of any expression following it when it is preceded by a falsy value. When the following expression is not executed, the return value is the value preceding &&, i.e., either false or nil.

try evaluates all arguments that are meant to be passed with the method in question, and cancels the application of the method when it is not defined. When the method call is not performed, the return value is nil.

Upvotes: 3

sled
sled

Reputation: 14635

Yes it does the same in this very example, however since ruby 2.3 we have a new operator for this, called "safe navigation operator":

def firstname
  shipping_address&.firstname
end

Upvotes: 1

Dharam Gollapudi
Dharam Gollapudi

Reputation: 6438

In essence, Yes.

Remember, it is added by rails. So it will not work in plain ruby projects.

Refer to Object#try for more info.

Upvotes: 0

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