## Sign

### Instructions

Create the `sign` function that takes one number argument
and return 1 if the number is positive, -1 if the number is negative
and 0 if the number is exactly 0
You must not just use `Math.sign`, make your own.

Create the `sameSign` function that takes 2 numbers as arguments and return true
if they both have the same sign, or false otherwise.


### Notions

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


### Code provided

> all code provided will be added to your solution and doesn't need to be submited.

```js
Math.sign = undefined
```