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    <p>The thing is, the return value of <code>initialize</code> is ignored. here's what happens when you call <code>A.new</code>:</p> <ul> <li><code>new</code> calls a special class method called <code>allocate</code> -- this returns an empty instance of the class</li> <li><code>new</code> then calls <code>initialize</code> on the object returned by <code>allocate</code>, and returns the object</li> </ul> <p>To do what you want to do, you need to override <code>new</code> and make it do what you want:</p> <pre><code>class A def self.new(args*) if(args[0]==1) B.new(*args[1..-1]) else C.new(*args[1..-1]) end end end </code></pre> <p>There is something else to consider though. If <code>A</code> is never really used on its own, you should be using some sort of factory method, or, just a simple if statement. Eg:</p> <pre><code>def B_or_C(param,args) (param == 1 ? B : C).new(args) end </code></pre> <p>The design really depends on what you are using them for. When you, for example, have a class that could be used to handle multiple versions of something, for example, HTML, you could have a main class <code>HTMLParser</code> which overrode <code>new</code> and could return any of its subclasses: <code>HTML1Parser</code>, <code>HTML2Parser</code>, <code>HTML3Parser</code>, <code>HTML4Parser</code>, and <code>HTML5Parser</code>.</p> <p>Note: You have to override the <code>new</code> method to the default in the sub-classes to prevent infinite looping:</p> <pre><code>def self.new(args*) obj=allocate obj.send(:initialize, *args) obj end </code></pre>
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    1. POHow to return new instance of subclass while initializing parent class?
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    1. USLinuxios
    1. USLinuxios
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    1. COThanks for you answer. However, when overriding `self.new` in `A` and calling `A.new(params)`, I'm getting an error: `SystemStackError: stack level too deep`. It seems, that calling `B.new` (or `C.new`) inside of `A.new` causes an infinite loop as the "constructors" of `B` and `C` are somehow calling the "constructor" of `A`, namely `A.new`.
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    2. COBecause of the heritage
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    3. CO@Torbjoern: See Edit.
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