How to Remove a Key-Value Pair from a Map in Ruby

How to Remove a Key-Value Pair from a Map in Ruby ?

Answer

To remove a key-value pair from a hash in Ruby, you can use the delete method. This method allows you to remove the key-value pair associated with the specified key.

✐ Examples

1 Removing a Key-Value Pair Using delete Method

We can remove a key-value pair from a hash in Ruby using the delete method, which removes the key-value pair associated with the specified key.

For example,

We start by declaring and initializing a hash named my_map with some key-value pairs. In this example, the hash has string keys and integer values.
We use the delete method to remove the key-value pair associated with the key 'two'. The delete method removes the key-value pair from the hash.
We print the contents of the hash to the console using the puts function to verify that the key-value pair has been removed.

Ruby Program

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

# Remove a key-value pair using delete method
my_map.delete('two')

# Print the contents of the hash
puts my_map

Output

{'one' => 1, 'three' => 3}

2 Handling Key Not Found Using delete Method

We can handle the case where a key is not found in a hash in Ruby using the delete method, which returns nil if the key is not present.

For example,

We start by declaring and initializing a hash named my_map with some key-value pairs. In this example, the hash has string keys and integer values.
We use the delete method to attempt to remove the key-value pair associated with the key 'four'. The delete method returns nil if the key is not found.
We print the contents of the hash to the console using the puts function to verify that the hash is unchanged.

Ruby Program

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

# Attempt to remove a non-existent key-value pair using delete method
my_map.delete('four')

# Print the contents of the hash
puts my_map

Output

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

3 Removing Multiple Key-Value Pairs Using delete Method

We can remove multiple key-value pairs from a hash in Ruby using the delete method, which removes the key-value pairs associated with the specified keys.

For example,

We start by declaring and initializing a hash named my_map with some key-value pairs. In this example, the hash has string keys and integer values.
We use the delete method to remove the key-value pairs associated with the keys 'one' and 'three'. The delete method removes the key-value pairs from the hash.
We print the contents of the hash to the console using the puts function to verify that the key-value pairs have been removed.

Ruby Program

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

# Remove multiple key-value pairs using delete method
my_map.delete('one')
my_map.delete('three')

# Print the contents of the hash
puts my_map

Output

{'two' => 2}

Summary

In this tutorial, we learned How to Remove a Key-Value Pair from a Map in Ruby language with well detailed examples.

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How to Remove a Key-Value Pair from a Map in Ruby