Check If a Hash's Keys Include All of a Set of Keys

Check if a hash's keys include all of a set of keys

%i[a b c d].all? {|s| hash.key? s}

Determine if hash contains any key from a set of keys?

Consider Enumerable.any?

[:a, :b, :e].any? {|k| h.key?(k)}

From IRB:

>> h = {:a => 1}; [:x].any? {|k| h.key?(k)}                    
=> false                                                                
>> h = {:a => 1}; [:x, :a].any? {|k| h.key?(k)}                
=> true

Happy coding.

Testing if a hash has any of a number of keys

No need to loop:

(hash.keys & keys).any? # => true

Explanation:

.keys returns all keys in a hash as an array. & intersects two arrays, returning any objects that exists in both arrays. Finally, .any? checks if the array intersect has any values.

How to check if a specific key is present in a hash or not?

Hash's key? method tells you whether a given key is present or not.

session.key?("user")

Check if a string includes any of the keys in a hash and return the value of the key it contains

I find this way readable:

hash_key_in_s = s[Regexp.union(h.keys)]
p h[hash_key_in_s] #=> "v1"

Or in one line:

p h.fetch s[Regexp.union(h.keys)] #=> "v1"

And here is a version not using regexp:

p h.fetch( h.keys.find{|key|s[key]} ) #=> "v1"

Check if two hashes have the same set of keys

Try:

# Check that both hash have the same number of entries first before anything
if h1.size == h2.size
    # breaks from iteration and returns 'false' as soon as there is a mismatched key
    # otherwise returns true
    h1.keys.all?{ |key| !!h2[key] }
end

Enumerable#all?

worse case scenario, you'd only be iterating through the keys once.

Check if multiple key-value pairs exist in a Ruby hash?

If you are using ruby >= 2.3, there is a fancy new Hash >= Hash operation that is conceptually similiar to a hypothetical contains?

Using your traits array:

trait = traits[0]
trait >= {"trait_type" => "Status", "value" => "Unbuilt"}
# => true

trait >= {"trait_type" => "Status", "value" => "Built"}
# => false

So you could try something like:

traits.select{|trait|
  trait >= filter_traits
}.length > 0
# => true

ruby if hash keys include text, return hash key

Use find:

if result = hash.keys.find {|k| k.include? number}
  #do some work
end

How do I check if my hash has a key from an array of strings?

strings = ['a', 'b', 'c']
hash = {:a => 'apple', :b => 'bob', :d => 'thing'}

has_key = hash.keys.map(&:to_s) & strings  # ['a', 'b']
has_key.any? # true

a one-liner that's similar, hash.keys.detect { |key| strings.include?(key.to_s) }.nil?

Find missing key in hash

You can make use of the Hash#keys method

REQUIRED_KEYS = %w(from subject to body)
hash = {
  "from"=>"abc@gmail.com", 
  "to"=>"def@gmail.com:ijk@gmail.com:lmn@gmail.com", 
  "subject"=>"hi", 
  "body"=>"there", 
  "cc" => "def@gmail.com:ijk@gmail.com", 
  "bcc" => "def@gmail.com:ijk@gmail.com"
}

REQUIRED_KEYS - hash.keys
#=> []

hash.delete('to')
#=> "def@gmail.com:ijk@gmail.com:lmn@gmail.com"

REQUIRED_KEYS - hash.keys
#=> ["to"]

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