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I'm looking to extract n random key-value pairs from a hash.
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The to_h method is defined in the array class. It works to convert an array to a hash in the form of key-value pairs. The method converts each nested array into key-value pairs. The method also accepts a block.
An array of hashes is useful when you have a bunch of records that you'd like to access sequentially, and each record itself contains key/value pairs. Arrays of hashes are used less frequently than the other structures in this chapter.
In Ruby, a hash is a collection of key-value pairs. A hash is denoted by a set of curly braces ( {} ) which contains key-value pairs separated by commas. Each value is assigned to a key using a hash rocket ( => ). Calling the hash followed by a key name within brackets grabs the value associated with that key.
Equality—Two hashes are equal if they each contain the same number of keys and if each key-value pair is equal to (according to Object#== ) the corresponding elements in the other hash. The orders of each hashes are not compared. Returns true if other is subset of hash.
Hash[original_hash.to_a.sample(n)] For Ruby 2.1,
original_hash.to_a.sample(n).to_h I don't know of such method. Still you can do something like:
h[h.keys.sample] If you need to sample more than one element the code will have to be a bit more complicated.
EDIT: to get key value pairs instead of only the value you can do something like:
keys_sample = h.keys.sample(n) keys_sample.zip(keys_sample.map{|k| h[k]) If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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