如何在 ruby​​ 中设置类范围常量？

Question

超级初学者易分红宝石题。我试图通过编程Project Euler 问题来学习一些红宝石。所以我有一个测试

class ProjectEuler_tests < Test::Unit::TestCase
  @solution = 123456 # Not the answer so as not to be a spoiler
  def test_problem_1
    assert_equal(@solution, ProjectEuler1.new.solve)
  end
end

但这不起作用，@solution 在测试运行时为零。在类范围内分配它的正确方法是什么？

Answer 1

Class constants 在 ruby​​ 中以大写字符开头：

class ProjectEuler_tests < Test::Unit::TestCase
  SOLUTION = 123456 # Not the answer so as not to be a spoiler
  def test_problem_1
    assert_equal(SOLUTION, ProjectEuler1.new.solve)
  end
end