Blockchain Development Programming Tutorials, Guides & Best Practices

You should use Etherscan when you need to read data from the Ethereum blockchain, such as querying transaction details, wallet balances, or token transfers. Etherscan is a powerful tool for building blockchain explorers or applications that focus on data analytics.

const axios = require('axios');

// Replace with your actual Etherscan API key
const apiKey = 'YOUR_ETHERSCAN_API_KEY';

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

// Etherscan API URL to fetch wallet balance
const url = `https://api.etherscan.io/api?module=account&action=balance&address=${address}&tag=latest&apikey=${apiKey}`;

async function getWalletBalance() {
  try {
    const response = await axios.get(url);
    const balanceInWei = response.data.result;

    // Convert balance from Wei to Ether
    const balanceInEther = balanceInWei / 1e18;
    console.log(`Wallet Balance: ${balanceInEther} ETH`);
  } catch (error) {
    console.error('Error fetching balance:', error);
  }
}

getWalletBalance();

Ethereum predates the ERC-20 token standard, which was introduced to standardize token creation on the blockchain. Since ETH doesn't conform to this standard, it cannot be directly used in many decentralized applications that rely on ERC-20 tokens. WETH solves this problem by allowing ETH holders to wrap their ETH into an ERC-20 compatible token that can be used across a wide range of DeFi protocols and dApps.

WETH essentially bridges the gap between ETH and the broader ERC-20 ecosystem, allowing ETH to function seamlessly in DeFi, token swaps, and other smart contract interactions.

anchor deploy

This command will deploy your program to the Solana cluster you’ve configured (either localnet, devnet, or mainnet).

4. Use Efficient Data Structures

• Choose data structures that minimize gas consumption. For example, mappings are generally more gas-efficient than arrays for storing large datasets.
• Example: Use a mapping instead of an array for storing user balances.

• string public message: Declares a public string variable to store the message.
• setMessage(string memory newMessage): A function to set a new message.
• getMessage() public view returns (string memory): A function to retrieve the stored message.

After writing the smart contract, the next step is to compile and deploy it.