array_change_key_case.markdown

array_change_key_case

{{notice: This function's solution uses a Ruby Hash object since Ruby arrays don't use associative key/value pairs. See Array for more details. }}

The default array_change_key_case behavior is to lowercase all of the keys in the array. In Ruby we use a combination of Hash#inject and String#downcase to achieve the same result.

{{code:php $array = array('cHaiRS' => 4, 'tAbLes' => 1);

$result = array_change_key_case($array, CASE_LOWER);
var_export($result);
// => array('chairs' => 4, 'tables' => 1);

}}

{{code:ruby hash = {'cHaiRS' => 4, 'tAbLes' => 1}

result = hash.inject({}) do |hash, keys|
  hash[keys[0].downcase] = keys[1]
  hash
end
p result
# => {"chairs"=>4, "tables"=>1}<a href="array_change_key_case.html" id="" title="array_change_key_case">array_change_key_case</a>

}}

Similarly, we can convert all of keys to uppercase using a combination of Hash#inject and String#upcase.

{{code:php $array = array('cHaiRS' => 4, 'tAbLes' => 1);

$result = array_change_key_case($array, CASE_UPPER);
var_export($result);
// => array('CHAIRS' => 4, 'TABLES' => 1);

}}

{{code:ruby hash = {'cHaiRS' => 4, 'tAbLes' => 1}

# upper
result = hash.inject({}) do |hash, keys|
  hash[keys[0].upcase] = keys[1]
  hash
end
p result
# => {"CHAIRS"=>4, "TABLES"=>1}

}}