How to Sort a Map by Values in Ruby

How to Sort a Map by Values in Ruby ?

Answer

To sort a hash by values in Ruby, you can use the `sort_by` method, which returns a sorted array of key-value pairs. You can then convert this array back to a hash using the `to_h` method. This method allows you to sort the hash based on values.

✐ Examples

1 Sorting a Hash by Values Using sort_by

We can sort a hash by values in Ruby by using the `sort_by` method, which returns a sorted array of key-value pairs. We then convert this array back to a hash using the `to_h` method.

For example,

We start by declaring and initializing a hash named unsorted_hash with some key-value pairs. In this example, the hash has string keys and integer values.
We use the sort_by method to sort the hash by values. This returns an array of key-value pairs sorted by values.
We convert the sorted array back to a hash using the to_h method.
We print the sorted hash to the console using the puts function to verify the sorting.

Ruby Program

unsorted_hash = { 'apple' => 3, 'banana' => 1, 'cherry' => 2 }

# Sort the hash by values
sorted_hash = unsorted_hash.sort_by { |k, v| v }.to_h

# Print the sorted hash
puts 'Sorted Hash by Values:'
sorted_hash.each { |key, value| puts "#{key}: #{value}" }

Output

Sorted Hash by Values:
banana: 1
cherry: 2
apple: 3

2 Sorting a Hash by Values in Descending Order

We can sort a hash by values in descending order in Ruby by using the `sort_by` method with a custom comparator, and then convert this array back to a hash using the `to_h` method.

For example,

We start by declaring and initializing a hash named unsorted_hash with some key-value pairs. In this example, the hash has string keys and integer values.
We use the sort_by method to sort the hash by values in descending order. This returns an array of key-value pairs sorted by values.
We convert the sorted array back to a hash using the to_h method.
We print the sorted hash to the console using the puts function to verify the sorting.

Ruby Program

unsorted_hash = { 'apple' => 3, 'banana' => 1, 'cherry' => 2 }

# Sort the hash by values in descending order
sorted_hash = unsorted_hash.sort_by { |k, v| -v }.to_h

# Print the sorted hash
puts 'Sorted Hash by Values (Descending):'
sorted_hash.each { |key, value| puts "#{key}: #{value}" }

Output

Sorted Hash by Values (Descending):
apple: 3
cherry: 2
banana: 1

3 Sorting a Hash with Numeric Keys by Values

We can sort a hash with numeric keys by values in Ruby by using the `sort_by` method, which returns a sorted array of key-value pairs. We then convert this array back to a hash using the `to_h` method.

For example,

We start by declaring and initializing a hash named unsorted_hash with some key-value pairs. In this example, the hash has integer keys and string values.
We use the sort_by method to sort the hash by values. This returns an array of key-value pairs sorted by values.
We convert the sorted array back to a hash using the to_h method.
We print the sorted hash to the console using the puts function to verify the sorting.

Ruby Program

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

# Sort the hash by values
sorted_hash = unsorted_hash.sort_by { |k, v| v }.to_h

# Print the sorted hash
puts 'Sorted Hash by Values:'
sorted_hash.each { |key, value| puts "#{key}: #{value}" }

Output

Sorted Hash by Values:
1: one
2: two
3: three

Summary

In this tutorial, we learned How to Sort a Map by Values in Ruby language with well detailed examples.

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