Multi Delegatecall | Solidity 0.8

[@0xmetario]

I love your content 😍♥️ Please make a video on flash loans and how to create whitelist function

[@mosipvp]

new day, new insane awesome tuts again. thankssssssssss t4sk

[@sdfsfsfd437]

Great videos! This is a super channel.

[@Ibrahim-oc5ql]

Batch thanks

[@Ts2pc]

In the last lesson(multicall), It seems we don't ask the called contract to inherit multicall contract? Why is it necessary in multidellegate call? (Alice -> Test inherits multi call -> multicall to Test (msg.sender is address(this)); Alice -> Test inherits multi delegatecall -> multi delegate call to Test (msg.sender is alice))?

[@xuan9793]

It's great to show vulnerabilities of the calls! But I don't fully understand why is it unsafe thou... Thanks for the video anyway!

[@smartcontractprogrammer]

several contracts were hacked with this bug

[@brunobernard86]

It took me some time also to actually understand it, Basically what is happening: Imagine you are buying multiple sweets and each is 1 dollar. The bug with delegatecall is: Lets say you want to buy 3 sweets (like in the video) but you handed over 1 dollar. Delegate call actually received 1$. The bug is msg.value is 1 for every consecutive calls. Making as if you paid $3 dollar instead of $1. Delegatecall do not exhaust the msg.value. So back to the code: if you paid an NFT For 1 eth. If you had the delegate call for the NFT you can mint all NFTs at the same price with 1 eth. Scary.

[@apah]

Is it possible to use multicall and multidelegatecall for state changing functions ? In this case do we have to make it payable and send enough funds to allow the contract to run the transactions ? Are these two methods the way to go to group multiple transactions ? (let's say to make many ERC20 transfers) Thanks

[@smartcontractprogrammer]

yes, no, yes

[@apah]

@@smartcontractprogrammer appreciate it

[@picardyoon1617]

Hello, I wonder if you success in using multicall and multidelegatecall for state changing functions ?

[@mattyost]

so this could be used to batch multiple transfer calls to multiple contracts?

[@viktor3512]

Buddy, fix the section of your tutorial regarding mapping You specified that the keyType can be "address,, bytes1 or uint" The _KeyType can be any built-in value type, bytes, string, or any contract or enum type. Other user-defined or complex types, such as mappings, structs or array types are not allowed. _ValueType can be any type, including mappings, arrays and structs.

[@D3athW1ng]

Regarding the error you pointed out here, I don't think I've seen this as an option with solidity but couldn't you limit the amount of values the array could take to one to prevent the error for the mint function?

[@smartcontractprogrammer]

Then multi-delegatecall can only call one function

[@D3athW1ng]

@@smartcontractprogrammer ahh point

[@spicer41282]

I love your Vids! Can you help us beginners by describing the context / situations this is used? 🙏 Thanks in advance!

[@smartcontractprogrammer]

Uniswap V3

[@MyNNiCo]

Hey, can you make a video about Deploying a Smart Contract from Frontend. I would have to normally run npx hardhat run scripts/deploy.js in my terminal to deploy. Is it possible to deploy in the frontend?

[@CarryOnRk]

I Love your every tutorial Can you also create a video on merkle tree?

[@roryoconnor8546]

Does the contract that your calling have to inherit the multideligate call contract? How would you go about calling other contracts that dont interit it?

[@smartcontractprogrammer]

Yes. Modify multi-delegatecall to be able to call different contracts

[@kewenlu4264]

I modified the contracts based on multiCall and it still works fine, is it necessary to inherit MultiCall as shown in video?

[@smartcontractprogrammer]

Separation of concerns - It's good programming practice

[@erth8096]

Please create a tutorial about how to make whitelist

[@hernanphillip334]

What would be the reason of using a multiDelegateCall inside your contract? I tried the same bug without being inherited and it didn't worked

[@smartcontractprogrammer]

batch transactions into multiDelegateCall

[@سرالحضارات-ي4ق]

We need video for strong code contract flash loan Arbitrage can make you profits more than gas Fees more than 10 times