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    <blockquote> <p>Given the example above, what is the difference between an object and a function?</p> </blockquote> <p>In Chrome, all these items are functions. In general however, a function is an object with the addition that it holds code and that you can call it. So, you can also just add properties to functions (like jQuery does: <code>$("selector")</code> or <code>$.ajax</code>).</p> <blockquote> <p>Do I write functions or objects in ES/JS?</p> </blockquote> <p>Well, obviously that depends on what you code. <code>function() {}</code> gives you a function; <code>{}</code> gives you an object. (Again, functions <em>are</em> objects in the end.)</p> <blockquote> <p>Why is Object a function and not an object?</p> </blockquote> <p><code>Object</code> is a function because you can call it, either as a constructor or not:</p> <pre><code>Object(); // returns an empty object new Object(); // same </code></pre> <p>Also, given that almost everything is an instance of <code>Object</code>, it follows that <code>Object</code> is a constructor and thus a function. (Note again that functions are also objects.)</p> <blockquote> <p>Is there any hierarchical structure to built in objects / functions?</p> </blockquote> <p>As for the ECMAScript built-in objects, there is in a sense. There are constructor functions (<code>String</code>) on the global object, functions for instances (<code>Array.prototype.forEach</code>), and "static" functions (<code>Object.defineProperty</code> which is meant to be used on objects, <code>Array.isArray</code> for arrays).</p> <blockquote> <p>Can built in objects / functions be redefined as something entirely different?</p> </blockquote> <p>Sure, you can do <code>Object = null</code>. But any code relying on <code>Object</code> will start throwing exceptions, so it's not recommended at all.</p> <blockquote> <p>Can built in objects / functions be undefined?</p> </blockquote> <p>No, an object is not undefined by definition. <code>undefined</code> is not an object and vice-versa. This holds for any object.</p> <blockquote> <p>Can built in objects / functions be assigned new features if they do not already support them natively?</p> </blockquote> <p>Yes, if e.g. <code>Array.prototype.forEach</code> does not exist, you could set it yourself. But it should be noted that such functions turn up in <code>for(var key in arr)</code> loops which again can cause code to behave differently. This can be solved using <code>Object.defineProperty</code> by using <code>{enumerable: false}</code>. But there is another caveat: the function is shared across the whole environment (e.g. the current page). If other code is also setting them you're experiencing collisions.</p> <blockquote> <p>If an object is defined in one browser and not another, how can I compensate for this?</p> </blockquote> <p>You can "shim" such functions. For e.g. ES5 functions such as <code>Array.prototype.forEach</code> there are shims available which make them available on older browsers as well. Underscore.js may be a good example.</p>
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Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

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