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    <p>The problem with some of the host objects (i.e. any non-native objects) in IE (and not only IE) is that they don't inherit from <code>Function.prototype</code> (and often neither from top level <code>Object.prototype</code>). Some host objects that <strong>might look like functions</strong> actually have nothing to do with functions except that they can be called. The fact that these objects don't inherit from <code>Function.prototype</code> means that they fail to be identified as functions with <code>instanceof</code> operator; that their constructor is not referencing <code>Function</code>; and that they lack all of the <code>Function.prototype.*</code> methods, such as <code>call</code> or <code>apply</code>. Even their internal [[Class]] property might not be that of "Function", as it is with any native object (note that [[Class]] can be inferred from the result of <code>Object.prototype.toString</code> value).</p> <p>This is actually expected, since <strong>host objects are not required</strong> to implement many things that native objects do (as per ECMA-262, 3rd ed.). It is perfectly allowed for a host object to, say, throw error on method invocation (e.g. <code>hostObject.hostMethod()</code>); or when passing it as an operand to standard operators like <code>delete</code> (e.g. <code>delete hostObject.hostMethod</code>). As you can see, it is also OK for callable host objects to NOT inherit from native <code>Function.prototype</code>. </p> <p>Such unpredictable (yet perfectly compliant) behavior is actually one of the main reasons why <strong>host objects augmentation is recommended against</strong>.</p> <p>But back to your <code>call</code> problem : )</p> <p>The thing about these "tricky" IE host objects is that they often implement internal [[Call]] method, and it is possible to invoke <code>call</code> and <code>apply</code> on them, although <strong>not directly</strong>.</p> <p>Here's a pattern to emulate <code>apply</code> invocation on an object that doesn't have it:</p> <pre><code>function f(){ return arguments }; Function.prototype.apply.call(f, null, [1,2,3]); // [1,2,3] </code></pre> <p><code>null</code> can be replaced with whatever context object should be called in, of course.</p> <p>And an example of <code>apply</code> invocation on host object that has no <code>call</code>:</p> <pre><code>// should work in IE6, even though `alert` has no `call` there Function.prototype.call.call(alert, window, 'test'); </code></pre> <p><strong>Applying it to your code</strong></p> <pre><code>// Calls Master.initialize borrowing from Function.prototype Function.prototype.apply.call(Master.initialize, Master, [1,"VC2"]); </code></pre>
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    1. POJavaScript: Problem with a ActiveX-Object and the apply()-Function
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    1. USJuan Mendes
    1. USkangax
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      1. VTUpMod
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    1. COThis is the real answer. Host object methods do not support `Function.prototype.apply` but you can always borrow it.
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      1. USJuan Mendes
 

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