I have some simple ico contracts for airdrop and presale with lock token future to lock token until ico end and I want to know how to connect it to token contra
Whenever I try to compile my solidity contract, the error ParserError: Source \"@OpenZeppelin/contracts/math/SafeMath.sol\" not found: File import callback not
My contract for ERC1155 marketplace to mint buy and sell the NFT. The nft is getting minted , However the NFT is not showing in market place and not able to pur
I have tried changing different versions of solc, solidity, and chainlink contracts but it doesn't work. Error: contracts/Lottery.sol:4:1: ParserError: Sourc
I have a Python script using Brownie that occasionally triggers a swap on Uniswap by sending a transaction to Optimism Network. It worked well for a few days (d
I am new to block chain. Suddenly I got a question did we can able to access the previous block data from the Ethereum block chain by block number. For example
I have tried to make a ERC20 token that takes a transaction fee on every transaction (buy/sell/transfer) and this transaction fee gets distributed amongst the h
I need to send ether from externally owned account to contract. All code I found so far looks like this contract Contract { mapping (address => uint) ba
I want to get the value that is inside of struct in Solidity, but I have no idea how to get it. pragma solidity >=0.4.21 <0.6.0; contract PlaceList {
I'm learning blockchain development recently and I'm implementing ERC721 contract to mint NFT and store the mapping of ownership. What if I deploy a second cont
I am learning solidity and got to know that interface and abstract are both classes that may contain unused functions. My doubt is: What is the difference betwe
I'm trying to get the price of some BSC token directly from the contract. Doing some searches, I found a mix of ideas with the snippet below. I'm sure the code
I created an array of structures and then tried to get the values of each account of an array. But I failed with an array while passing the address variable whi
I have locally created a DApp in Solidity for Ethereum framework. I have a smart contract, a js file (using web3 API) and html file. What I want to achieve is t
I want to compile my ethereum HelloWorld.sol smart contract. In all the tutorials is that you do it like this: var solc = require('solc'); var compiledContract
I write the code below. It seems it has a problem with the "signed_txn = w3.eth.account.sign_transaction(transaction, private_key=private_key" part. I face to t
Is it possible to return an array in solidity? // SPDX-License-Identifier: MIT pragma solidity >=0.8.0 <0.9.0; pragma experimental ABIEncoderV2; contract
I am developing an application on Ethereum blockchain. I use Solidity for contract and Nethereum c# library to connect to the contract. I am somehow new in Ethe
I am writing a script for a smart contract that I'll deploy using hardhat. I'm confused on the difference between .deploy() and .deployed(), what does each one
I'm trying to complete the simple collectible NFT tutorial from this freeCodeCamp video. (I'm getting stuck on the script that starts exactly where the link is