array_keys

• This function’s solution uses a Ruby Hash object since Ruby arrays don’t use associative key/value pairs. See Array for more details.

  To get the keys of an associative hash in Ruby, we can use the Hash#keys method.

  PHP

  $person = array('name' => 'Walter', 'age' => 25);
  $result = array_keys($person);
  var_export($result);
  // => array(0 => 'name', 1 => 'age')

  Ruby

  person = {:name => "Walter", :age => 25}
  p person.keys
  # => [:age, :name]

  We can specify a value to match when retrieving keys by adding a second argument to PHP’s array_keys function. We can achieve a similar result in Ruby using a block.

  PHP

  $fruit = array('apple', 'orange', 'grape', 'apple');
  $result = array_keys($fruit, 'apple');
  var_export($result);
  // => array(0 => 0, 1 => 3)

  Ruby

  fruit = ["apple", "orange", "grape", "apple"]
   
  result = []
  fruit.each_with_index do |value, key| 
    result.push(key) if value == "apple"
  end
  p result
  # => [0, 3]

  see also

  • array_values
  • array_key_exists

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