All Questions

I'm new to working with Ethereum smart contracts and would appreciate some guidance by the community on a task that I'm trying to solve. This is the contract I want to use - https://github.com/chatch/...

I am trying to execute the following script: module.exports = (callback)=> { Message.setProvider(web3.currentProvider); const MyContract = require("~/Truffle programs/...

When importing one Solidity contract into another, what’s the difference between importing it and accessing it using the is keyword, vs. importing it and just instantiating an object of it? Here’s ...

I lost my jaxx backup phrase. I have private keys to two ERC20 tokens (ICN and SALT). I want to use MEW to regain access/link to my tokens on the blockchain. What are the exact steps in MEW to use ...

binance smart chain v1.0.7 When new node complete syncing, RPC returns 0x0 values few hours.Can I fix that? Please help me

My transaction https://etherscan.io/tx/0xd4f9905b14e26ee96b243f47e734e1b7880dc2a23f8f847dae786fca0f3f9888 has failed and was marked as reverted 15 hours ago. Though i don't think my ETH wallet has ...

All Web3js functions works correctly in my NODE (10.7.0) localhost server but the same configuration return the next error in my remote NODE webserver (same configuration and versions). Any idea? ...

I've been trying to make my contract be callable by metamask (so a popup will occur telling the user to confirm) but it does not seem to work, heres what I have come up with so far. Can anyone give me ...

I am having difficulty understanding getting the price within the contract. So I created 2 different methods (one using SDK and other one using ethers.js) When I try the SDK, I get 3839.62 When I try ...

Intro: I am trying to use ERC721Enumerable in my NFT contract so I can get the set of all NFTs owned by a particular address. Research: The ERC721Enumerable contract was implemented to enumerate ...

How can I implement code that returns whether a token is in the ERC721 or ERC1155 standard, knowing both the contract address and the tokenId? What I tried is that I call a function that exists only ...

When implementing the ERC721 contract standard, how strictly does one have to stick to the naming conventions of the method signatures - as spelled out by the standard? Take for example the ownerOf ...

Im trying to send a query to Pancakeswap's router function getAmoutsOut here the code for importing the contract using ethers ABI: const router = new ethers.Contract('...

i used web3j to Transacting with a smart contract. this is my Contract function which i want to intertact with. function usersRegister(string _id, string _password){ Equipment e = equipments[msg....

Check this transaction, it is sent by a mining pool with 0.08$ fee, and it is almost mined with in minutes. How is this possible? Current average gas price is 150, that is almost 10$

I have this withdrawal function but an error happens: TypeError: "send" and "transfer" are only available for objects of type "address payable", not "address". -...

When I try to send Ether I get an error code that says:ENCODING/HEX: ODD LENGTH HEX STRING. Here the history, my PC had had issues working properly so I did a system recovery, then rebooted Mist ...

I am really new into contracts and tokens, I wanted to learn how to deploy a contract, so I grabbed someone else's contract and tried to deploy it on BSC. I was following tutorial on youtube and ...

Can someone explain to me how to get the amount of tokens that have been transfered from a transaction receipt? I came across some posts that said I can get it out of the data property from the ...

Does anyone know how to solve this? This is the first time I use Metamask to swap ShibaInu, however it's failed. https://etherscan.io/tx/...

Besides receiving ethers, for which there is a dedicated receive function, what is a practical use case of fallback? I can't think of a case when it would be desirable for a contract to execute a ...

Here's what I've been able to get going to far. I can open the blockchain database but I can't seem to create a valid blockchain object (nor call the blockchain.getBlock() function successfully). I'...

Can anyone explain to me, why the transaction object I receive via web3 always has a value of 0? When I open up the transactionhash in etherscan, it shows under the to field which is named "...

I was wondering if I e.g. use balanceOf(account[1]) += tax if the amount will also updated on Metamask and TrustWallet? Here is an example code which I found where the addresses will be in mapping and ...

Let's say you have a private blockchain, a DApp with an workflow to store and retrieve data from that blockchain. Now there is a need to store binary files and access it in a permissible way. One way ...

I've been experimenting with ChainLink recently and am fascinated of what it can do. I already used the code provided here ChainLink Docs in Python and got it to work. However, I've been searching all ...

I'm trying to deploy my Smart Contract onto the Rinkeby test network. Everything is working fine, my rinkeby account is also having enough ethers. And also using HDWalletProvider, I am able to access ...

How can we maintain the balances of two different bep-20 tokens in a single smart contract called Handler lets suppose? I am trying to write a function that transfers the second type and the first ...

I'm trying to open ethereum studio, but the tab closes a second after it opens. I've tried opening it through both chrome and edge.

I made an effort to cut out all the irrelevant parts of the code and get a minimal version still able to reproduce the error, these are the 3 smart contracts involved: // SPDX-License-Identifier: MIT ...

Error: connect ECONNREFUSED /home/sanya/.ethereum/geth.ipc at PipeConnectWrap.afterConnect [as oncomplete] (net.js:1106:14) errno: 'ECONNREFUSED', code: 'ECONNREFUSED', syscall: '...

I am extremely new to crypto. I withdrew USDC to an address using the Binance Smart Chain Network. I have located the transaction on BscScan https://bscscan.com/token/...

i've codded a script using js to trigger a buy on uniswap. the way i achieved this is through importing uniswaps smart contracts using this line of code: const router = new ethers.Contract(addresses....

I get "DeclarationError: Undeclared identifier" on _totalSuppy and _balances. Could anyone help me figure this out? Parent contract pragma solidity ^0.8.0; import "./IERC20.sol"; ...

My question is not very technical from an implementation point of view, but I am looking for advice to achieve a specific use case using blockchain tech. I would greatly appreciate any insights or ...

I bought ETC via website https://classicetherwallet.com/ by generating the wallet in 2017. After that as the market went down. I was diverted and never looked into. However recently i came to know ...

Here is my code pragma solidity ^0.8.2; import "https://github.com/Uniswap/uniswap-v2-periphery/blob/master/contracts/interfaces/IUniswapV2Router02.sol"; contract Test_Swap{ address ...

During a recent token migration from token A to token B, a large number of token A were held by a number of people in an IDEX address (where it was ready to trade). The IDEX address is part of a smart ...

While learning solidity, I copy-pasted this code from: https://docs.soliditylang.org/en/v0.8.4/types.html // SPDX-License-Identifier: GPL-3.0 pragma solidity >=0.6.4 <0.9.0; contract Example { ...

I've been getting this error when I try and deploy a contract with a constructor on multiple pieces of code. I use the correct complier version too creation of MyContract errored: Error encoding ...

Could someone enable a download only for an NFT holder? What would be the mechanism for this?

Based on the data structure of Ethereum blocks and transactions which is also represented here, we know the following sentences about the transactions receipts: 1- The transactions receipts are ...

when reading through the specs of Merkle-Patricia-Trees, I was wondering if branch nodes of storage tries ever contain values? It is my understanding, that the last array element of a branch node ...

Issue: When I initiate "start.bat", I am noticing that the Miner only recognizes that I have (1) GPU being recognized. Although, I do have 6 of these cards all properly connected, powered on and ...

I am trying to make trades on 1inch and frequently get an error that reads Fail with error 'Min return not reached'. My gas prices are set very high because I need these trades to be as fast as ...

Constantly getting logs like this in my geth instance WARN [05-08|14:06:32.143] Served eth_signTransaction conn=195.123.216.5:60142 reqid=1 t="83.324µs" err="tx fee (...

Excuse me, What should data I pass in _data bytes when I call tokenFallback and transferAndCall and approveAndCall? function transferAndCall(address _recipient, uint256 _amount, bytes _data) function ...

Created a virtualenv with python3.6 and performed the following steps git clone https://github.com/ethereum/vyper.git cd vyper make I see following error(s): Downloading https://files.pythonhosted....

Is it possible to send a fixed amount of ether to smart contract from an account every time a function is executed or button is clicked? No input fields should be used.

Token was created under ERC223. Every transfer that I have done received: ERC-20 Token Transfer Error (Unable to locate corresponding Transfer Event Logs), Check with Sender. Please help to check and ...