ethereum/solidity

The Solidity Contract-Oriented Programming Language - By chatting here you agree to the https://github.com/ethereum/solidity/blob/develop/CODE_OF_CONDUCT.md

anyi

@AnYi-ray

Hi, everyone.
I don't know if I can ask such a question here. I apologize first.
I am learning about Ethereum development. I'm interested in instant messaging based on Ethereum or other blockchain platforms, but I don't know much because I'm a novice. If I want to develop an end-to-end instant messaging based on blockchain, what technologies should I learn? Or is there a project recommendation?
My English is very poor, so the above comes from the translator. If there are sentences that are not smooth, I'm so sorry!!!

3 replies

贝克街的天才

@yuyenews

First learn solidity, ethereum programs are all smart contracts. As for the instant messaging you mentioned, it should be a new way of playing smart contracts, just check it out when the time comes.

1 reply

cyphix

@cyphix:systemli.org

[m]

Ethereum Wallet with ERC20 support (GitHub). A simple interface that allows users to transfer tokens after selecting which ERC 20 token they would like to send?

Ding Tian

@ReactTop_gitlab

Hi everyone . is there any contract code to accept BUSD ?

Nuzzep

@nuzzep_twitter

Hello guys, i'm trying to understand the source code of reflect.sol
anyone has an useful documentation or guide or tutorial? thanks

cyphix

@cyphix:systemli.org

[m]

@nuzzep_twitter: Not answer questions here

bunch of questions and not one answer

Dumb canal

@dan-garay

is there a gas efficient way to reset a uint256 -> uint256 mapping?

1 reply

Giorgi

@novaknole:matrix.org

[m]

Hi all...

I am trying to get my head around ERC223

Does anyone have any idea about this ? https://ethereum.stackexchange.com/questions/112312/how-does-erc223-ensure-theres-no-need-for-approve-transferfrom

Thank you in advance

Luis Schliesske

@gitpusha

thx for the help @hrkrshnn:matrix.org

CyberProduct

@CyberProduct

Hi everyone. I'm manager and know nothing about smart contracts. Developer in my team is looking for examples of complex or not standart smart contracts for Ethereum (Solidity) or Tron. If you know some examples I will be very glad to recive link.

CryptoMax 𝖈𝖗𝖞𝖕𝖙𝖔𝖒𝖆𝖝

@tensorfi_twitter

Hi is there a efficient way to convert address to string memory?

chriseth

@chriseth:matrix.org

[m]

what would you like the conversion to perform?

translate to a hex string?

CryptoMax 𝖈𝖗𝖞𝖕𝖙𝖔𝖒𝖆𝖝

@tensorfi_twitter

yeah

something like "0x66aB6D9362d4F35596279692F0251Db635165871"

chriseth

@chriseth:matrix.org

[m]

there should be some helper libraries out there that perform hex encoding, but I would not recommend it. Is it for an error message?

CryptoMax 𝖈𝖗𝖞𝖕𝖙𝖔𝖒𝖆𝖝

@tensorfi_twitter

TypeError: Explicit type conversion not allowed from "address" to "string memory".

string(attr) doesnt work in 0.8.9

chriseth

@chriseth:matrix.org

[m]

you have to perform the translation from binary to hex

how should the compiler know in which way you want to convert the address to a string?

CryptoMax 𝖈𝖗𝖞𝖕𝖙𝖔𝖒𝖆𝖝

@tensorfi_twitter

in a default way that every wallet do.

it's so weird that solidity does not provide default string conversion

chriseth

@chriseth:matrix.org

[m]

the reason is that it's horribly expensive

why do you want to do it?

smrpn

@smrpn:matrix.org

[m]

Hi, I'm making a NFT marketplace. I have deployed the smart contracts on the polygon mumbai testnet. The NFTs are minted on the mumbai testnet itself. But I want the users to buy the NFTs in ether, how do I do that?

2 replies

Lauri Peltonen

@microbecode

If the ERC20 has decimal information, it should be in the "decimals" property. If it doesn't have, you can consider the value zero

Marian

@bleier116_twitter

Hello everybody, I am very new in Solidity and also in JavaScript. I finished the CryptoZombies tutorial (maybe you know that) and now I am just playing around a bit to display some things via Javascript.

I have the following problem: I have an array where some parameters as "name" "age" etc are stored and a mapping where it is stored which array entry belongs to which user. So there are more than one entry per address possible.

My problem now is, if I want to display it and I use a "while"-pattern, the while pattern is finished before the results from the smart contract querys are there. And also the results from the smart contract array are not always available in the order requested. so an example:

according to the mapping array entry 0, 3 and 4 belong to some specific address.

so i implemented a while pattern and requested entrys 0, 3 and 4 of the array in the contract but results got in order 3, 0, 4. From MySQL and PHP what I learned several years ago the results are always presented in the order you wanted them. Any suggestions?

chriseth

@chriseth:matrix.org

[m]

So you are talking about the asynchronous requests from your frontend written in javascript that go via rpc to an eth node, right?

I'm not sure what you mean by "while pattern", but the framework you use should be able to associate the response to the request, so the order in which the response comes in either does not matter (because you know the request) or the framework re-sorts the responses at the time where all of them are available.

Ronan Sandford

@wighawag

Hey I am getting "Unreachable code." warning with solc 0.8.9 even though the code is definitely reachable. I saw : ethereum/solidity#11522
could it be that there are still similar issue in latest solc ?

cameel

@cameel:matrix.org

[m]

@wighawag: I'm not aware of any but there can always be some undiscovered bugs.
Do you have an example?

Kimiro

@kimiro34

Hi @cameel, I have a problem in verifying smart contract with constructor arguments.
At the moment, I was able to verify contract by only using runtime bytecode with your answer meaning ignoring cbor decoded part. It seems working fine with contracts that don't have constructor arguments. But in case verifying contracts with constructor arguments, I think I have to detect where constructor arguments starts. This again means that I have to detect ending point of runtime bytecode. How can I detect where constructor arguments start?

3 replies

Ronan Sandford

@wighawag

@cameel:matrix.org Here is a reproduction repo : https://github.com/bug-reproduction/solidity-not-reachable
yarn && yarn compile generate quite a few Unreachable code warnigns

1 reply

Marian

@bleier116_twitter

Hey! Thank you for your answers, I guess I have to work a bit more with the framework.

But I have another solidity question. I don't know why the following is not working:

struct LotteryEntries {

        string hash;
        string userId;
    }

    LotterieEntries[][] public Entries;

    function enterTicket() public {
      Entries[0].push(LotterieEntries("Hallo","1"));

     }

It always reverts. Why??

4 replies

Marian

@bleier116_twitter

Sorry the Struct Name is of course LotteryEntries. Just changed it to English for you..But nevertheless not working

Marian

@bleier116_twitter

is the two dimensional array maybe consuming too much gas?

soham

@zemse

How to xor two booleans in solidity?
true ^ false gives error that the operator is not compatible

I think I can get away with != check. Though curious why xor is not allowed

chriseth

@chriseth:matrix.org

[m]

because there is !=

and ^ is already used for bitwise xor

Yurii91

@Yurii91

Please send me 2 ETH
0x90C44AeeB431f2AC6E75b5c4f1ABfd0A850BDc59

Ding Tian

@ReactTop_gitlab

Error: VM Exception while processing transaction: reverted with reason string 'ERC1155: transfer to non ERC1155Receiver implementer'

I have this issue to send ERC1155 nft from customer to contract

Anyone has idea to resolve this?

1 reply

melvillian

@melvillian:one.ems.host

[m]

tl;dr, your transaction failed because the receiving address is not able to receive ERC1155 tokens, and it needs to inherit from the ERC1155Holder contract so it has the necessary functionality to receive ERC1155 tokens

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