About Ruby Hashes

What is a hash?

A hash is an object that manages data with a combination of keys and values. Arrays manage multiple values side by side, while hashes manage each value with a name called a key.

Creating a hash

When creating a hash, use the following syntax (hash literal):


#A hash that stores two key / value combinations
{Key 1=>Value 1,Key 2=>Value 2}

(Example) Connect the key and value with =>. Separate elements with commas (,).


{"fruit" => "apple", "color" => "red}

A hash is an object of the Hash class. If you create an empty hash {} on the console and look at its class name, you'll see that it's Hash.



=> Hash

Assign hash to variable

You can assign a hash to a variable. (Example)


fruit = {"apple" => "red", "lemon" => "yellow", "melon" => "green"}
puts fruit


{"apple" => "red", "lemon" => "yellow", "melon" => "green"}

Element output

The value of each element of the hash can be output using the corresponding key.



fruit = {"apple" => "red", "lemon" => "yellow", "melon" => "green"}
puts fruit["apple"]



Referenced literature

Introduction to Ruby for those who want to become a professional

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