At the beginning, it was the first argument.
But I looked more closer à my uses cases and the `console.log` API.
`console.log` could be used that way :
```
console.log("The awesome value is : %s", value)
```
And I watched at the use of the comma operator. And, I have choosen to follow the comma operator evaluation.
That said the last value of the operation will be returned.
```
const a = () => (add = 1 + 2, add * 3)
const a = () => log(add = 1 + 2, add * 3)
```
Both will return 9. And every step of the comma operation will be printed.