class_exists

  • Classes in Ruby are reference by a constant (a variable beginning with an uppercase letter). We can check if a class is defined by verifying that the constant exists for the class name using Module.const_defined?.

    PHP

    class Car {}
$exists = class_exists('Car');
var_export($exists);
// => true

    Ruby

    class Car; end
p Module.const_defined?("Car")
# => true

    see also

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