How To Hash An Array Ruby

In this blog post, we will learn how to convert an array into a hash using the Ruby programming language. Hashes are useful data structures that store key-value pairs, where the key is unique and the value is associated with that key. Converting an array to a hash can make it easier to manipulate and access data, especially when dealing with large datasets.

Converting an Array to a Hash

Let’s say we have an array of key-value pairs, with each key followed by its value:

    array = [:name, "Alice", :age, 30, :city, "New York"]
    

To convert this array into a hash, we can use the Hash[] method:

    hash = Hash[*array]
    puts hash
    

The output will be:

    {:name=>"Alice", :age=>30, :city=>"New York"}
    

Alternatively, you can use the Enumerable method each_slice to split the array into key-value pairs, and then convert each pair using the to_h method:

    hash = array.each_slice(2).to_h
    puts hash
    

The output will be the same as before:

    {:name=>"Alice", :age=>30, :city=>"New York"}
    

Converting an Array of Arrays

If you have an array of arrays, where each nested array contains a key-value pair, you can convert it to a hash using the to_h method:

    array_of_arrays = [[:name, "Alice"], [:age, 30], [:city, "New York"]]
    hash = array_of_arrays.to_h
    puts hash
    

The output will be:

    {:name=>"Alice", :age=>30, :city=>"New York"}
    

Converting an Array of Objects

If you have an array of objects and you want to convert it into a hash, you can use the map method combined with the to_h method. Let’s say you have an array of objects, each containing a person’s name and age:

    class Person
      attr_accessor :name, :age
    
      def initialize(name, age)
        @name = name
        @age = age
      end
    end
    
    people = [
      Person.new("Alice", 30),
      Person.new("Bob", 25),
      Person.new("Charlie", 22)
    ]
    

To convert this array of objects into a hash, where the keys are the names and the values are the ages, you can use the following code:

    hash = people.map { |person| [person.name, person.age] }.to_h
    puts hash
    

The output will be:

    {"Alice"=>30, "Bob"=>25, "Charlie"=>22}
    

Conclusion

In this blog post, we learned how to convert an array into a hash using Ruby. Converting arrays to hashes can be useful when working with large datasets or when you want to provide an easier way to access and manipulate data. We covered how to convert a basic array of key-value pairs, an array of arrays, and an array of objects into hashes. Understanding these techniques can help improve your efficiency and productivity as a Ruby programmer.