Call a function when variable changes
<p>I'm looking for some way to bind a function to variable change.</p>

<pre><code>var arr = [],
    str = 'hello';
onChange(arr, console.log);
onChange(str, console.log);
arr.push('element');  // console output: ["element"]
str += ' stack over flow';  // console output: "hello stack overflow"
</code></pre>

<p>— or something like this.</p>

<p>Is there any kinda-mini-framework written in pure JS or with jQuery for this?</p>
