ProgramGuruTo set a default value for a key in a hash in Ruby, you can use the fetch method with a default value, or the default_proc.
We can set a default value for a key in a hash in Ruby using the fetch method, which returns the value for a given key or a specified default value if the key is not found.
For example,
my_map with some key-value pairs. In this example, the hash has string keys and integer values.fetch method to set a default value for a key. The fetch method takes the key and a default value to be returned if the key is not found in the hash.fetch method to the key in the hash to set the default value.puts function.my_map = {
'one' => 1,
'two' => 2,
'three' => 3
}
# Set a default value using fetch method
my_map['four'] = my_map.fetch('four', 4)
# Print the updated hash
puts my_map{'one' => 1, 'two' => 2, 'three' => 3, 'four' => 4}We can set a default value for a key in a hash in Ruby using the default_proc, which sets a block to be executed when a non-existent key is accessed.
For example,
my_map with some key-value pairs. In this example, the hash has string keys and integer values.default_proc method to set a default value for keys. The default_proc method sets a block that returns a default value when a non-existent key is accessed.default_proc and set the default value.puts function.my_map = {
'one' => 1,
'two' => 2,
'three' => 3
}
# Set a default value using default_proc
my_map.default_proc = proc { |hash, key| hash[key] = 4 }
my_map['four']
# Print the updated hash
puts my_map{'one' => 1, 'two' => 2, 'three' => 3, 'four' => 4}We can set multiple default values for keys in a hash in Ruby using the default_proc, which sets a block to be executed when non-existent keys are accessed.
For example,
my_map with some key-value pairs. In this example, the hash has string keys and integer values.default_proc method to set multiple default values for keys. The default_proc method sets a block that returns default values when non-existent keys are accessed.default_proc and set the default values.puts function.my_map = {
'one' => 1,
'two' => 2,
'three' => 3
}
# Set multiple default values using default_proc
my_map.default_proc = proc { |hash, key| hash[key] = key == 'four' ? 4 : 5 }
my_map['four']
my_map['five']
# Print the updated hash
puts my_map{'one' => 1, 'two' => 2, 'three' => 3, 'four' => 4, 'five' => 5}In this tutorial, we learned How to Set a Default Value for a Key in a Map in Ruby language with well detailed examples.