I am working on a project where I need to send ether from an user to a smart contract and from the smart contract to the user. The smart contract is code in Sol
An address in Solidity can be an account or a contract (or other things, such as a transaction). When I have a variable x, holding an address, how can I test if
Basically, I'm trying to make the smart contract be able to take exactly 0.05 eth ONLY when the cooldown timer is set to 0. The Dapp I'm creating is a first com
I am interacting with my own smart contract. It's a very simple one. // SPDX-License-Identifier: MIT pragma solidity ^0.8.0; contract ERC20 { string public n
My code for concatenating 2 strings is pretty simple: string baseUrl = "http://localhost:8080/"; string url = baseUrl.append(url_secret); But I have got an err
I can't deploy compiled free ton solidity smartcontract through tonos-cli. > tonos-cli deploy Hello.tvc tonos-cli.conf.json Config: /ton/solidity_deploy/hel
Free TON Solidity. How to get hash from data encoded into cell? tvm.hash() analogue?
Free TON Solidity code or execution error. Can't understand my mistake, I already compact the code to the minimum: cat ./SimpleStorage.sol pragma solidity >=
I would like to compute the sha256 of a string in a Free TON-Solidity contract, I do it by storing the string in a TvmBuilder and then passing it as a TvmSlice
I'm writing an NFT smart contract using the OpenZeppelin ERC721Full contract. I'm able to mint NFTs, but I want to have a button that enables them to be bought.
I get this Truffle error when I compile. I have tried adding payable to the addresses but it won't work. This is the error: TypeError: Member "transfer" not fo
i have copied a contract from openzappline. but when i compile it on remix it gives me the error....that utils/context.sol is not found. here is the import prag
I am using Hardhat hackathon boilerplate and calling my smart contract's (address 1c0, addresses shortened for clarity) function MyContract#addProduct from the
I have two contract, I write in in one file, named Sum.sol. The sum contract invoke Add contract. I just want to test cross-contract invoking. If I didn't put t
This the validation json I got for my nft toke 34 HTTP 200 OK Allow: GET, OPTIONS Content-Type: application/json Vary: Accept { "valid": true, "token_u
I am developing an NFT collection using ERC721 token. But I would like to know how a particular nft is held by a particular customer? I am sensing there are two
I want to list two collections on Opensea but instead of creating two smart contracts for that, I want to create only one (to save gas fees of uploading a contr
I want to know how OpenSea system read contract and call functions. So, I try to write a ERC721 contract without import any other code. // SPDX-License-Identifi
I am currently learning about NFTs and I reached the point where I deployed the contract and I can mint and everything going well. The only missing part is roya
I have a Smart Contract that represent ERC20 token. I already deployed the smart contract on Binance Testnet using HardHat. I have a deployed Smart Contract add