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I have an array of strings, and want to make a hash out of it. Each element of the array will be the key, and I want to make the value being computed from that key. Is there a Ruby way of doing this?
For example:
['a','b'] to convert to {'a'=>'A','b'=>'B'}
665
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.
Creating an array of hashes You are allowed to create an array of hashes either by simply initializing array with hashes or by using array. push() to push hashes inside the array. Note: Both “Key” and :Key acts as a key in a hash in ruby.
Convert the key from a string to a symbol, and do a lookup in the hash. Rails uses this class called HashWithIndifferentAccess that proves to be very useful in such cases.
Ruby's arrays and hashes are indexed collections. Both store collections of objects, accessible using a key. With arrays, the key is an integer, whereas hashes support any object as a key.
You can:
a = ['a', 'b']
Hash[a.map {|v| [v,v.upcase]}]
Ruby's each_with_object method is a neat way of doing what you want
['a', 'b'].each_with_object({}) { |k, h| h[k] = k.upcase }
%w{a b c}.reduce({}){|a,v| a[v] = v.upcase; a}
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