❓Trivia: Reverting a transaction if conditions aren't met is an essential tool for literally all smart contracts!

But as of v0.8.4 of solidity, which one of these is more gas efficient?

🔮 And the answer is... B is more gas efficient!

🤔 But maybe not in the way you'd expect...

Let's look at our sample contract here to test.

👇

If our `doStuff` and `doOtherStuff` functions pass, they actually end up using the same amount of gas, so their is NO gas savings there!

However, if your transaction REVERTS (ie: You don't send enough value with your transaction) that's when we see a slliight gas saving.

Our `doOtherStuff` that uses the `revert` statement saves a tiny bit of gas - which is nice.

But the BIGGEST savings actually comes right at the deploy time.

In our `require` statement, we have to save a whole big string to our contract - our revert does not!

Our Test2 contract is a TON of gas comparatively! So right now, it's better to use:

if (x) revert error

However, plans for a try/catch or adding errors to require is in progress, to make it easier for developers to read and write:
github.com/ethereum/solidity/issues/11278

Shoot me a like, retweet, and a follow if you learned something!

EDIT: More information: blog.soliditylang.org/2021/04/21/custom-errors/