Difference

[OmarWaqar123]

Lesson: Raffle/Lottery

1. can you please tell me that while writing deploy scripts for VRFCoordinatorV2Mock.sol , if BASE_FEE means that we have to give 0.25 LINK per each request to get the random number then what is the difference between BASE_FEE and GAS_PRICE_LINK .

2. if in BASE_FEE we have to give 0.25 LINK then why are we giving it ethereum instead of Link meaning why are we parsing ethereum ether.utils.parseEther("0.25");

I also looked at the ether documentation to know what utils.parseEther() does and this what the docs says.

So as far as I understood ethers.parseEther()`` is used to parse the ethers(ethereum) into wei . So I hope you have understood my question that why are we giving etheruem instead of LINK``` to BASE_FEE.

my 00-deploy-mocks.js

const BASE_FEE = ethers.utils.parseEther("0.25"); // 0.25 is the premium. It costs 0.25 LINK per request
const GAS_PRICE_LINK = 1e9;

[othaime-en]

Hey @OmarWaqar123 from the documentation, we see that ethers.utils.parseEther() provides the string representation of a BigNumber instance in wei. This means we convert whatever ETH we pass in into the string representation in wei (18 decimals). This is just a fancy way of saying that it is a unit conversion functionality. So we simply multiply by 18 decimals places (1e18). technically, it doesn't work on ETH explicitly, it works on anything that has the a unit representation same as wei. So whatever unit you have if it is equal to 1e18, ethers.utils.parseEther() can work just fine.
Back to our scenario, if you look at LINK token documentation, you can see that its smallest unit called JUELS is 1e18 which is similar to wei. So just like 1 ETH = 1e18 wei, 1 LINK = 1e18 Juels. This makes it so that we can easily use ethers.utils.parseEther() on LINK too because it is simply a unit conversion functionality, not necessarily tied to ethers alone.

[OmarWaqar123]

thanks

[alymurtazamemon]

@OmarWaqar123

BASE_FEE you guess it correctly is a fee that we have to pay on every request we made for a random number.
GAS_PRICE_LINK is a price set by chainlink that node operators will pay when they will call our functions, and this price varies from time to time as the price of that blockchain token increases or decreases.

And as @othaime-en said above that the parseEther("0.25") conversion is equivalent to LINK's JUELS that is why here we are using the parseEther method for conversion that is available to us, you can also write it like this 2500000000000000000.

And this is just on the mock side, on a testnet and on a mainnet we only deposit LINK tokens on Chainlink dashboards.

[OmarWaqar123]

thanks