About Ruby Hashes (continued)

Article about the previous hash

Equivalence comparison of hashes

You can check if the hashes are the same by comparing the hashes with ==. At this time, if all the keys and values are the same, true is returned. True if the keys and values are all the same, even if they are in a different order.

(Example)

x = { 'a' => 1, 'b' => 2, 'c' => 3}
y = { 'b' => 2, 'c' => 3, 'a' => 1}
x == y # => true

Get the number of elements

You can use the size method (= length) to find out the number of hash elements.

{ 'a' => 1, 'b' => 2, 'c' => 3 }.size # => 3

Delete element

You can delete the element corresponding to the key specified by the delete method. Finally, if you print the hash, you can see that the element has been removed.

menus = { 'food' => 'rice', 'drink' => 'water', 'dessert' => 'cake' }
menus.delete('food') # => "rice"The value of the deleted element will be the return value
puts menus                             # => {"drink" => "water", "dessert" => "cake"}

Referenced literature

Introduction to Ruby for those who want to become a professional

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