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POJavascript: Do I need to put this.var for every variable in an object?
 

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  1. POJavascript: Do I need to put this.var for every variable in an object?
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    <p>In C++, the language I'm most comfortable with, usually one declares an object like this:</p> <pre><code>class foo { public: int bar; int getBar() { return bar; } } </code></pre> <p>Calling <code>getBar()</code> works fine (ignoring the fact that <code>bar</code> might be uninitialized). The variable <code>bar</code> within <code>getBar()</code> is in the scope of class <code>foo</code>, so I don't need to say <code>this-&gt;bar</code> unless I really need to make it clear that I'm referring to the class' <code>bar</code> instead of, say, a parameter.</p> <p>Now, I'm trying to get started with OOP in Javascript. So, I look up how to define classes and try the same sort of thing:</p> <pre><code>function foo() { this.bar = 0; this.getBar = function() { return bar; } } </code></pre> <p>And it gives me <code>bar is undefined</code>. Changing the <code>bar</code> to <code>this.bar</code> fixes the issue, but doing that for every variable clutters up my code quite a bit. Is this necessary for every variable? Since I can't find any questions relating to this, it makes me feel like I'm doing something fundamentally wrong.</p> <hr> <p>EDIT: Right, so, from the comments what I'm getting is that <code>this.bar</code>, a property of an object, references something different than <code>bar</code>, a local variable. Can someone say why exactly this is, in terms of scoping and objects, and if there's another way to define an object where this isn't necessary?</p>
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    1. CO`.bar` is an object property, not a variable. So yes, to get the property from an object, you need to do so via some reference to that object. If `this` references your object, then `this.bar` will give you that property.
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    2. CO`this.bar` is not the same as `bar`. However you can do `var bar = this.bar` which will make `bar` reference `this.bar`
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    3. CO@Loktar but only if `this.bar` is an object or an array...
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