## Abs

### Instructions

Create a `isPositive` function that takes a number as
parameter and return true if the given number is
stricly positive, or false otherwise

Create the `abs` function that takes one number argument
and returns its absolute value.
You are not allowed to use `Math.abs`, make your own.


### Notions

- [nan-academy.github.io/js-training/examples/functions.js](https://nan-academy.github.io/js-training/examples/functions.js)
- [nan-academy.github.io/js-training/examples/ternary.js](https://nan-academy.github.io/js-training/examples/ternary.js)
- [devdocs.io/javascript/global_objects/math/abs](https://devdocs.io/javascript/global_objects/math/abs)


### Code provided
```js
Math.abs = undefined
```