How to Check if a Value Exists in a Map in Ruby

How to Check if a Value Exists in a Map in Ruby ?

Answer

To check if a value exists in a hash in Ruby, you can use the value? method. This method returns a boolean value indicating whether the hash contains the specified value.

✐ Examples

1 Checking if a Value Exists Using value? Method

We can check if a value exists in a hash in Ruby using the value? method, which returns true if the hash contains the specified value and false otherwise.

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 value? method to check for a specific value in the hash. The value? method returns a boolean value indicating whether the hash contains the specified value.
We print the result to the console using the puts function.

Ruby Program

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

# Check if a value exists using value? method
value_exists = my_map.value?(2)

# Print the result
puts "Does value 2 exist? #{value_exists}"

Output

Does value 2 exist? true

2 Checking if a Value Does Not Exist Using value? Method

We can check if a value does not exist in a hash in Ruby using the value? method, which returns false if the hash does not contain the specified 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 value? method to check for a specific value in the hash. The value? method returns a boolean value indicating whether the hash contains the specified value.
We print the result to the console using the puts function.

Ruby Program

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

# Check if a value does not exist using value? method
value_exists = my_map.value?(4)

# Print the result
puts "Does value 4 exist? #{value_exists}"

Output

Does value 4 exist? false

3 Checking Multiple Values Using value? Method

We can check if multiple values exist in a hash in Ruby using the value? method, which returns true if the hash contains the specified value and false otherwise.

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 value? method to check for multiple values in the hash. The value? method returns a boolean value indicating whether the hash contains the specified value.
We print the results to the console using the puts function.

Ruby Program

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

# Check if multiple values exist using value? method
value_exists_one = my_map.value?(1)
value_exists_four = my_map.value?(4)

# Print the results
puts "Does value 1 exist? #{value_exists_one}"
puts "Does value 4 exist? #{value_exists_four}"

Output

Does value 1 exist? true
Does value 4 exist? false

Summary

In this tutorial, we learned How to Check if a Value Exists in a Map in Ruby language with well detailed examples.

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How to Check if a Value Exists in a Map in Ruby