Category "solidity"

EtherScan access needed on Test net

We are developing application on VS code with Ganache. So everything will be local as it is Ganache. As explained in following link, we cannot use etherScan fun

How to find out if an Ethereum address is a contract?

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

Timed Advertisements Solidity Contract

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

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