Insert Lead paragraph here. "Smart Contract receive ethers ONLY when contract provide fallback() or receive() function. " Is this statement true or not? [ ] true [ ] false 1pragma solidity ^0.8.0; 23// SPDX-License-Identifier: MIT 4contract MyContract { 5receive() external payable {} 6fallback() external …

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According to Solidity doc, msg.sender (address): sender of the message (current call) tx.origin (address): sender of the transaction (full call chain) tx.origin means the first account that initial transaction. However, the msg.sender is exactly the account that triggers the function. Example Let's take a look at …

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Random is important in blockchain games. However, there is no true random number on solidity. The best practice is to use Chainlink VRF. This article will show you how to attack a CoinFlip contract. The following code is the CoinFlip contract, which was rewritten from Ethernaut. 1// SPDX-License-Identifier: MIT 2pragma …

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Token uri can be fixed. Client(e.g. opensea) will replece {id} with tokenId. Take this code as example. 1// SPDX-License-Identifier: MIT 2pragma solidity ^0.8.4; 34import "@openzeppelin/contracts/token/ERC1155/ERC1155.sol"; 5import "@openzeppelin/contracts/access/Ownable.sol"; 6import …

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Add Fantom Testnet on Metamask Visit Chainlist. https://chainlist.org/ connect your metamask search Fantom Add to Metamask Get some $FTM via faucet paste your wallet addres, then click request. https://faucet.fantom.network/ Modify Truffle Setting Open truffle-config.js file, add a new fantom_test into newwork …

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