How to Clear All Key-Value Pairs from a Map in Ruby - Step by Step Examples

How to Clear All Key-Value Pairs from a Map in Ruby ?

Answer

To clear all key-value pairs from a hash in Ruby, you can use the clear method. This method removes all elements from the hash, leaving it empty.

✐ Examples

1 Clearing All Key-Value Pairs Using clear Method

We can clear all key-value pairs from a hash in Ruby using the clear method, which removes all elements from the hash.

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 clear method to remove all key-value pairs from the hash.
We print the size of the hash using the size method to verify that the hash is empty.

Ruby Program

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

# Clear all key-value pairs using clear method
my_map.clear

# Print the size of the hash
puts "Size of the hash after clearing: #{my_map.size}"

Output

Size of the hash after clearing: 0

2 Clearing an Already Empty Hash

We can use the clear method on an already empty hash in Ruby, and it will still leave the hash empty.

For example,

We start by declaring and initializing an empty hash named my_map. In this example, the hash has string keys and integer values.
We use the clear method to remove all key-value pairs from the hash, even though it is already empty.
We print the size of the hash using the size method to verify that the hash is still empty.

Ruby Program

my_map = {}

# Clear the hash using clear method
my_map.clear

# Print the size of the hash
puts "Size of the hash after clearing: #{my_map.size}"

Output

Size of the hash after clearing: 0

3 Clearing a Hash After Inserting Elements

We can insert key-value pairs into a hash and then clear all key-value pairs using the clear method.

For example,

We start by declaring and initializing a hash named my_map and inserting some key-value pairs into it. In this example, the hash has string keys and integer values.
We use the clear method to remove all key-value pairs from the hash.
We print the size of the hash using the size method to verify that the hash is empty.

Ruby Program

my_map = {}
my_map['one'] = 1
my_map['two'] = 2
my_map['three'] = 3

# Clear all key-value pairs using clear method
my_map.clear

# Print the size of the hash
puts "Size of the hash after clearing: #{my_map.size}"

Output

Size of the hash after clearing: 0

Summary

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

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