Category "solidity"

Why is a transaction consuming gas for a public view function?

I deployed the following smart contract on Ropsten ethereum test network and afterwards I tried making a transaction using @alch/alchemy-web3 npm package (Yes,

How is hardhat implicitly knowing deployer address?

I am new to using hardhat and I was trying to figure out how it is working. The documentation seems a little bit fuzzy as there are multiple layers of abstracti

problem associated with web3.py installation on windows10

I tried installing web3, but I got the error in the picture below. I installed VS build tools using the link VS Code provided but I'm still getting the same err

ERC721 NFT not showing in opensea (related to the metadata)

I was creating the DApp and succeeded to mint NFT in Rinkeby using IPFS (pinata) & Nethereum (C#). Now, I can get TokenURI using tokenURI function in ERC721

String concatenation in solidity?

How do I concatenate strings in solidity? var str = 'asdf' var b = str + 'sdf' seems not to work.. I looked up the documentation and there is not much mentione

Error with <string>.append() in ton-solidity: Different number of components on the left hand side (1) than on the right hand side (0)

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

Chai should be bignumber equal doesn't work

I am requireing chai like this const BigNumber = web3.BigNumber; require('chai').use(require('chai-bignumber')(BigNumber)).should(); and during test let balanc

Everscale tonos-cli. Can't deploy a contract. Error: failed to create inbound message: Encode deploy message failed: Wrong parameters count

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

Everscale-Solidity. How to get hash from data encoded into cell? tvm.hash analogue?

Free TON Solidity. How to get hash from data encoded into cell? tvm.hash() analogue?

Everscale Solidity error by timeout: code: 3025 Contract execution was terminated with error

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 >=

What is the difference between debot fetch and debot start?

I have few different options in the command line: fetch and start. What is the difference between them?

Incorrect result of sha256 of a string in a Everscale Solidity smart contract

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

How to transfer a NFT from one account to another using ERC721?

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.

not found utils/context.sol when i import from openzepplin

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

when i try to run solidity-coverage with truffle run coverage then I got this error

I try to run solidity coverage for testing test case and its coverage but when I run coverage command its give error like this : - command used (truffle run cov

Hardhat – What are the strange calls to my smart contract?

I am using Hardhat hackathon boilerplate and calling my smart contract's (address 1c0, addresses shortened for clarity) function MyContract#addProduct from the

How to test smart contract with cross-contract invoke using truffle?

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

How to implement smart contract to add eth address record to refer the specific ENS subdomain name in solidity

I have wrote the smart contract for creating ENS subdomain name. I need to pass the reference ETH address record for that created subdomain name. pragma sol

How to identify Who holds an NFT for how long?

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

Why my ERC721 contract in Opensea can't work normally (Without any code of openzeppelin github)

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