How to Remove Key-Value Pairs from a Map Based on Values in Ruby - Step by Step Examples

How to Remove Key-Value Pairs from a Map Based on Values in Ruby ?

Answer

To remove key-value pairs from a hash in Ruby based on values, you need to iterate through the hash and check each value. If the value matches the specified condition, remove the corresponding key-value pair.

✐ Examples

1 Removing Key-Value Pairs with Specific Value

We can remove key-value pairs from a hash in Ruby by iterating through the hash and removing pairs with a specific value.

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_if method to iterate through the hash. For each key-value pair, we check if the value matches the specified value 2.
If the value matches, the delete_if 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 pairs have been removed.

Ruby Program

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

# Remove key-value pairs with specific value
my_map.delete_if { |key, value| value == 2 }

# Print the contents of the hash
puts my_map

Output

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

2 Removing Key-Value Pairs with a Range of Values

We can remove key-value pairs from a hash in Ruby by iterating through the hash and removing pairs with values within a specified range.

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_if method to iterate through the hash. For each key-value pair, we check if the value falls within the specified range (e.g., between 2 and 3 inclusive).
If the value falls within the range, the delete_if 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 pairs have been removed.

Ruby Program

my_map = {
    'one' => 1,
    'two' => 2,
    'three' => 3,
    'four' => 4
}

# Remove key-value pairs with values in the range [2, 3]
my_map.delete_if { |key, value| value >= 2 && value <= 3 }

# Print the contents of the hash
puts my_map

Output

{'one' => 1, 'four' => 4}

3 Removing Key-Value Pairs with Condition-Based Values

We can remove key-value pairs from a hash in Ruby by iterating through the hash and removing pairs with values that meet a specified condition.

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 string values.
We use the delete_if method to iterate through the hash. For each key-value pair, we check if the value meets a specified condition (e.g., if the length of the string is 3).
If the condition is met, the delete_if 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 pairs have been removed.

Ruby Program

my_map = {
    'one' => 'one',
    'two' => 'two',
    'three' => 'three',
    'four' => 'four'
}

# Remove key-value pairs where value length is 3
my_map.delete_if { |key, value| value.length == 3 }

# Print the contents of the hash
puts my_map

Output

{'three' => 'three', 'four' => 'four'}

Summary

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

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How to Remove Key-Value Pairs from a Map Based on Values in Ruby - Step by Step Examples