# Truthiness

Javascript (and other languages) have something called [Truthiness](http://www.comedycentral.com.au/throwbacks/videos/the-colbert-report-the-very-first-episode-clips#the-word-truthiness). Ok, it's actually called [**`Truthy`**](https://www.sitepoint.com/javascript-truthy-falsy/) or [**`Falsy`**](https://www.sitepoint.com/javascript-truthy-falsy/). It is the idea that we can ***infer*** something is true, similar to assuming.

### Falsy

If something does not exist (like `NaN`) or has a value equating to zero, it is considered `false`. For example, an empty string of `""` would be considered false. It has no value.

### Truthy

If the data has value (other than specifically `NaN`, zero, or `false`) it is considered `true`, because it has value. For example, `1 == '1'` will result in `true` because they are equal in value (Javascript converts on-the-fly). However, `1 === '1'` will return `false` because they are not *exactly* equal (one is a numeric value, the other a string).

{% hint style="info" %}
`NaN` stands for Not a Number. Think of it like "undefined" or "does not exist".\
Note: division by zero gives an answer of infinity.
{% endhint %}