How to Convert a Map to an Array of Keys in Ruby - Step by Step Examples

How to Convert a Map to an Array of Keys in Ruby ?

Answer

To convert a hash to an array of keys in Ruby, you can use the keys method. This method returns an array of all keys in the hash.

✐ Examples

1 Converting a Hash to an Array of Keys Using keys Method

We can convert a hash to an array of keys in Ruby using the keys method, which provides an array of all keys in the hash.

For example,

We start by declaring and initializing a hash named my_hash with some key-value pairs. In this example, the hash has string keys and integer values.
We use the keys method to get an array of the keys in the hash.
We store the array of keys in a variable named keys_array.
We print the keys to the console using the puts function to verify the conversion.

Ruby Program

my_hash = {
  'one' => 1,
  'two' => 2,
  'three' => 3
}

# Convert hash to an array of keys
keys_array = my_hash.keys

# Print the keys
puts "Keys: #{keys_array}"

Output

Keys: ["one", "two", "three"]

2 Converting an Empty Hash to an Array of Keys

We can also convert an empty hash to an array of keys in Ruby using the keys method, which returns an empty array when the hash is empty.

For example,

We start by declaring an empty hash named empty_hash with string keys and integer values.
We use the keys method to get an array of the keys in the empty hash.
We store the array of keys in a variable named empty_keys_array.
We print the keys to the console using the puts function to verify that the array is empty.

Ruby Program

empty_hash = {}

# Convert empty hash to an array of keys
empty_keys_array = empty_hash.keys

# Print the keys
puts "Keys: #{empty_keys_array}"

Output

Keys: []

3 Converting a Hash to an Array of Keys After Adding Elements

We can convert a hash to an array of keys in Ruby after adding elements using the keys method, which provides an updated array of all keys in the hash.

For example,

We start by declaring an empty hash named dynamic_hash with string keys and integer values.
We add some key-value pairs to the hash using the hash's index notation.
We use the keys method to get an array of the keys in the hash after adding elements.
We store the array of keys in a variable named dynamic_keys_array.
We print the keys to the console using the puts function to verify the updated list of keys.

Ruby Program

dynamic_hash = {}

# Add elements to the hash
dynamic_hash['one'] = 1
dynamic_hash['two'] = 2
dynamic_hash['three'] = 3

# Convert hash to an array of keys after adding elements
dynamic_keys_array = dynamic_hash.keys

# Print the keys
puts "Keys: #{dynamic_keys_array}"

Output

Keys: ["one", "two", "three"]

Summary

In this tutorial, we learned How to Convert a Map to an Array of Keys in Ruby language with well detailed examples.

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How to Convert a Map to an Array of Keys in Ruby - Step by Step Examples