Blockchain Development Programming Tutorials, Guides & Best Practices

• crypto.randomBytes is part of Node.js, so it requires no external dependencies. This makes it ideal for Node.js environments where minimal dependencies are desired.
• ethers.randomBytes requires the installation of the ethers.js library, which is primarily designed for blockchain-related projects. This is useful if you're already working with Ethereum, but it adds an external dependency to the project.

• crypto.randomBytes:
• Takes a single argument specifying the number of bytes.
• Always requires a size input; no default value is provided.
• ethers.randomBytes:
• Optionally takes the number of bytes to generate.
• If no argument is provided, it defaults to generating 32 bytes.

• Greater Than:

  console.log(num1.gt(num2)); // true

const ethers = require('ethers');

// Replace with your Infura or other Ethereum node provider URL
const provider = new ethers.JsonRpcProvider('https://mainnet.infura.io/v3/YOUR_INFURA_PROJECT_ID');

// Replace with the ERC-20 token contract address (e.g., USDT, DAI)
const contractAddress = '0xTokenContractAddress';

// Replace with the wallet address you want to query
const walletAddress = '0xYourEthereumAddress';

// ERC-20 token ABI (just the balanceOf function)
const abi = [
    'function balanceOf(address owner) view returns (uint256)'
];

// Create a contract instance
const contract = new ethers.Contract(contractAddress, abi, provider);

async function getTokenBalance() {
    try {
        // Query the balance
        const balance = await contract.balanceOf(walletAddress);

        // Convert balance to a human-readable format (tokens usually have 18 decimals)
        const formattedBalance = ethers.utils.formatUnits(balance, 18);

        console.log(`Token Balance: ${formattedBalance}`);
    } catch (error) {
        console.error('Error fetching token balance:', error);
    }
}

// Call the function to get the token balance
getTokenBalance();

• Contract Address: Replace '0xTokenContractAddress' with the address of the ERC-20 token (e.g., USDT, DAI, or any other ERC-20 token).
• Wallet Address: Replace '0xYourEthereumAddress' with the wallet address whose token balance you want to query.
• ABI: We are using a minimal ABI with just the balanceOf function, which is all that’s required to query the token balance.

• Rate Limits: Infura’s free tier provides a generous number of requests (e.g., 100,000 requests per day) and supports more requests as you scale. This makes it more suitable for real-time dApps.
• Pricing: Infura’s paid plans offer higher limits and additional features like access to Layer 2 networks.

• Use Etherscan if:
• You only need to read blockchain data.
• You want to build tools for analytics or explorers.
• You don’t need to send transactions or interact directly with smart contracts.
• Use Infura if:
• You need to interact with the Ethereum blockchain in real-time.
• You’re building dApps, wallets, or tools that require transactions.
• You need to write data to the blockchain, such as sending Ether or deploying contracts.

• Bytecode and ABI: The contract bytecode is the compiled contract, and the ABI defines the contract’s interface. You need both to deploy the contract.
• The contract will be deployed using your Infura provider and wallet, and once mined, it will return the deployed contract address.

In this tutorial, you learned how to use Ethers.js with Infura to send Ether, interact with smart contracts, and deploy contracts on the Ethereum blockchain. This setup allows you to interact with the blockchain in real-time without the need to run your own Ethereum node, making it easier to develop decentralized applications (dApps) and other blockchain-based services.