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POConstructor inheritance; what am I not getting here?
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copied!<p>I'm trying to understand inheritance in Javascript, but this code (tested in Firebug) doesn't work the way I'm expecting. What am I not understanding about it?</p> <pre><code>var A = function(v){ this.v = v || 'foo'; } A.prototype.shout = function(){ alert(this.v); } var B = function(){}; B.prototype = new A; var test = new B('bar') test.shout() // returns 'foo' </code></pre> <p>What I'm expecting is that when I assign <code>test</code> the property <code>this.v</code> is set to "bar". As far as I understand JS prototypical inheritance setting <code>B</code>'s prototype to <code>A</code>'s means everything in <code>B</code> is overwritten. I would expect then that it's constructor is overwritten, and that calling <code>new B('bar')</code> would execute <code>A</code>'s constructor with the parameter "bar".</p> <p>If my understanding is incorrect, could someone please correct me. It would also be good to find the solution to what I'm looking to do:</p> <pre><code>// constructors from above B.prototype.yell = function(){ alert('hello world'); } var test1 = new B('bar'), test2 = new B('spam'), test3 = new B('eggs'); </code></pre> <p>...so that the JS objects I'm creating follow a similar inheritance pattern to standard OOP and therefore <code>B</code> would inherit <code>A</code>'s constructor and methods.</p> <p><strong>Edit:</strong></p> <p>After reading the comments, I believe a better question would be to ask how would one overwrite <code>B</code>'s constructor with <code>A</code>'s?</p>

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