我可以在Ruby 1.9.x中使用無參數函數嗎？

所以我正在通過Ruby Koans，我遇到了一個我認爲特定於ruby 1.9.x的問題。我可以在Ruby 1.9.x中使用無參數函數嗎？

def test_calling_global_methods_without_parentheses 

    result = my_global_method 2, 3 
    assert_equal 5, result 
end

我得到這個：

[email protected]:~/code/ruby_projects/ruby_koans$ rake 
(in /home/james/code/ruby_projects/ruby_koans) 
cd koans 
/home/james/.rvm/rubies/ruby-1.9.2-p180/bin/ruby path_to_enlightenment.rb 
/home/james/code/ruby_projects/ruby_koans/koans/about_methods.rb:21:in `eval': (eval):1: syntax error, unexpected tINTEGER, expecting keyword_do or '{' or '(' (SyntaxError) 
assert_equal 5, my_global_method 2, 3 
           ^
    from /home/james/code/ruby_projects/ruby_koans/koans/about_methods.rb:21:in `test_sometimes_missing_parentheses_are_ambiguous' 
    from /home/james/code/ruby_projects/ruby_koans/koans/edgecase.rb:377:in `meditate' 
    from /home/james/code/ruby_projects/ruby_koans/koans/edgecase.rb:449:in `block in walk' 
    from /home/james/code/ruby_projects/ruby_koans/koans/edgecase.rb:460:in `block (3 levels) in each_step' 
    from /home/james/code/ruby_projects/ruby_koans/koans/edgecase.rb:458:in `each' 
    from /home/james/code/ruby_projects/ruby_koans/koans/edgecase.rb:458:in `block (2 levels) in each_step' 
    from /home/james/code/ruby_projects/ruby_koans/koans/edgecase.rb:457:in `each' 
    from /home/james/code/ruby_projects/ruby_koans/koans/edgecase.rb:457:in `each_with_index' 
    from /home/james/code/ruby_projects/ruby_koans/koans/edgecase.rb:457:in `block in each_step' 
    from /home/james/code/ruby_projects/ruby_koans/koans/edgecase.rb:455:in `catch' 
    from /home/james/code/ruby_projects/ruby_koans/koans/edgecase.rb:455:in `each_step' 
    from /home/james/code/ruby_projects/ruby_koans/koans/edgecase.rb:448:in `walk' 
    from /home/james/code/ruby_projects/ruby_koans/koans/edgecase.rb:470:in `block in <top (required)>' 
rake aborted! 
Command failed with status (1): [/home/james/.rvm/rubies/ruby-1.9.2-p180/bi...] 
/home/james/code/ruby_projects/ruby_koans/Rakefile:86:in `block in <top (required)>' 
(See full trace by running task with --trace) 
[email protected]:~/code/ruby_projects/ruby_koans$

我看了在GitHub上聲稱最近完成了Koans（在過去的2個月）的幾個不同的版本庫，我只是完成看到了我使用的答案（第一段代碼片段）。那麼，這是與我的代碼，我的Ruby安裝或其他東西？

來源

2011-03-17 jrg

您得到的錯誤不是您列出的代碼;它來自它下面的代碼。相關文件的See line 20。該票據說：

注意：我們使用下面的eval因爲示例代碼被認爲是語法上是無效

來源

2011-03-18 00:01:35

謝謝！這也是一個提醒，我*真的*需要閱讀更多的錯誤... – jrg 2011-03-18 00:21:15

我不知道爲什麼，但是代碼被這樣的評價：

def test_calling_global_methods_without_parentheses 
    assert_equal 5, my_global_method 2, 3 
end

的問題是，這是ambiguos，可能意味着assert_equal(5, my_global_method(2, 3))或assert_equal(5, my_global_method(2), 3)。在這個特定的情況下，你必須使用圓括號。

來源

2011-03-18 00:00:13

不要忘了刪除方法調用和第一個參數之間的空間。

做這個

eval "assert_equal 5, my_global_method(2,3)"

，而不是

eval "assert_equal 5, my_global_method (2,3)" #beware of the space!

來源

2013-08-27 13:16:22 Rabiees

我可以在Ruby 1.9.x中使用無參數函數嗎？

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