Hash Table Implementation in Ruby

hash.rb

# Meant to work with strings as keys.

class MyHash
	def initialize(size: 100)
		@size = size
		@hash = Array.new(size)
	end

	attr_accessor :hash

	def insert(key, value)
		i = hashing_function(key)
		@hash[i] ||= []
		if @hash[i].find { |arr| arr.first == key }
			return "Key exists."
		else
			@hash[i] << [key, value]
		end
	end

	def delete(key)
		i = hashing_function(key)
		arr = lookup(key)
		@hash[i].delete(arr)
	end

	def lookup(key)
		i = hashing_function(key)
		if @hash[i]
			result = @hash[i].find { |arr| arr.first == key }
		else
			nil
		end
		result
	end

	def hashing_function(key)
		key.chars.map(&:ord).reduce(&:*) % @size
	end
end