Ruby: How to Convert a String to Boolean

Ruby: How to convert a string to boolean

def true?(obj)
  obj.to_s.downcase == "true"
end

String true and false to boolean

As far as i know there is no built in way of casting strings to booleans,
but if your strings only consist of 'true' and 'false' you could shorten your method to the following:

def to_boolean(str)
  str == 'true'
end

Converting anything to a boolean in Ruby

No, !! is the cleanest way.

If you're on Rails however, you could check out object.present?. It returns false for all of the following:

false
nil
""
[]
{}

The last three return true with !! but will return false with present?.

How to change my boolean output to a string value in ruby

Just use a ternary:

reply.rsvp ? "true" : "false"

Replace "true" and "false" by whatever strings you want to display.

Convert true-false strings to boolean & Skip the rest in a hash

I think this does what you want. I have not calculated the O of it.
I used the Marshal#dump/load trick to do a deep copy of the object before manipulating it.

mp = "most_popular"
obj = Marshal.load(Marshal.dump(h))
obj.each_key {|k| obj[k].each {|v| v[mp] = v[mp] == "true" ? true : false if v[mp] }}

Also see Cary's comment below for a slightly more terse version of the inner block.

In Rails, how can I get a string from a boolean?

You can use my_boolean_value.to_s. Basically it will convert booleans to string.

You can also do "#{my_boolean_value}"

Note: If my_boolean_value can be .nil? or anything other then true/false then your solution in the question is the best and simplest way to do it. You can use following way as well if you don't want to use ternary operator,

(!!my_boolean_value).to_s

But I still think from readability and maintainability point of view, you should use the solution given in the question. Reason would be, you are doing double negation can be confusing if you don't put comments around.

Need to convert a Boolean from Postgres (== String) to a Ruby Boolean

ActiveRecord has a method called ActiveRecord::ConnectionAdapters::Column.value_to_boolean it uses internally to convert any true-like value to a Ruby true value.

You can use it in your code.

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