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  1. PO
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    <p>I am not quite sure what <code>js_funct</code> should do. <code>res</code> in it is completely useless:</p> <pre><code>def js_funct if @flipped_on res = my_funct if res return res.length end end return nil end </code></pre> <p>You could just say <code>my_funct.length</code> and get the length of whatever the function <code>my_funct</code> returns.</p> <p>But it seems that following thing confuses you: in Ruby, functions (we call them methods, as they always belong to an object) are not first-class objects. So you can't say <code>res = my_funct</code>, hoping that you would assign a <em>function</em> to a variable, as you would in JavaScript. In Ruby, that line would first <em>execute</em> <code>my_funct</code> method, and put its <em>result</em> into variable named <code>res</code>.</p> <p>If you would like to check if a method is defined, you can, for example, use <a href="http://www.ruby-doc.org/core/classes/Object.html#M001005" rel="nofollow"><code>Object#respond_to?</code></a> method.</p> <p>If you would like to wrap your method into an object in order to pass it around, you should use <a href="http://www.ruby-doc.org/core/classes/Object.html#M001038" rel="nofollow"><code>Object#method</code></a> method. But in Ruby it's more common to pass <em>blocks</em> (closures) around, rather than whole <em>methods</em>. You are in fact doing that every time you use <code>map</code>, <code>each</code> or other common Ruby methods.</p> <p>If you would want to see how a particular task is coded in Ruby, you should say what the task is. Your example doesn't tell that.</p>
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    1. POBest Ruby idiom for logic like this
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    1. USMladen Jablanović
    1. USMladen Jablanović
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    1. COBut that would mean that it would be called twice. The assumption is that my_funct is expensive. I want to call my_funct once, then test its result. If not nil, then do something on its return.
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    2. COAnd you need to assume that my_funct may be nil if it fails. So you need handle all cases.
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    3. COAh, I missed the point of `res` then. If it's expensive operation, you should consider wrapping `my_funct` into an accessor, caching the result in an instance variable. Anyway, I like your starting code better, it's more readable than the one-liner, and can be shortened by couple of lines without losing readability.
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      1. USMladen Jablanović
 

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