Web3.js vs ethers.js in Blockchain / Solidity - Hands-On Comparison

Comparing Web3.js and ethers.js for Ethereum Interaction

📖 Scenario: You want to interact with the Ethereum blockchain to check the balance of an Ethereum address. Two popular JavaScript libraries for this are Web3.js and ethers.js. This project will help you understand how to set up and use both libraries to get the balance of the same Ethereum address.

🎯 Goal: Build a script using both Web3.js and ethers.js to fetch and display the balance of the Ethereum address 0x742d35Cc6634C0532925a3b844Bc454e4438f44e using each library.

📋 What You'll Learn

Use the exact Ethereum address 0x742d35Cc6634C0532925a3b844Bc454e4438f44e

Create a provider connected to the Ethereum mainnet using Infura

Use both Web3.js and ethers.js

Fetch the balance in wei and convert it to ether

Print the balances as strings with the labels 'Balance with Web3.js:' and 'Balance with ethers.js:'

💡 Why This Matters

🌍 Real World

Developers use Web3.js and ethers.js to build web applications that interact with Ethereum blockchain, such as wallets, decentralized apps, and analytics tools.

💼 Career

Understanding these libraries is essential for blockchain developers, smart contract engineers, and anyone working on Ethereum-based projects.

1

Setup Web3.js with Infura Provider

Create a variable called Web3 by requiring the web3 library. Then create a variable called web3 that connects to the Ethereum mainnet using the Infura URL https://mainnet.infura.io/v3/YOUR_INFURA_PROJECT_ID. Also, create a variable called address and set it to the string '0x742d35Cc6634C0532925a3b844Bc454e4438f44e'.

Blockchain / Solidity

const Web3 = require('web3');
// Your code here

Need a hint?

Use require('web3') to import Web3.js. Then create a new Web3 instance with the Infura URL. Set the address exactly as given.

2

Setup ethers.js with Infura Provider

Create a variable called ethers by requiring the ethers library. Then create a variable called provider using new ethers.providers.JsonRpcProvider with the same Infura URL https://mainnet.infura.io/v3/YOUR_INFURA_PROJECT_ID.

Blockchain / Solidity

const Web3 = require('web3');
const web3 = new Web3('https://mainnet.infura.io/v3/YOUR_INFURA_PROJECT_ID');
const address = '0x742d35Cc6634C0532925a3b844Bc454e4438f44e';

const ethers = require('ethers');
// Your code here

Need a hint?

Use require('ethers') to import ethers.js. Then create a new JsonRpcProvider with the Infura URL.

3

Fetch Balance Using Both Libraries

Write an async function called getBalances. Inside it, use web3.eth.getBalance(address) to get the balance in wei and convert it to ether using web3.utils.fromWei. Also, use provider.getBalance(address) to get the balance with ethers.js and convert it to ether using ethers.utils.formatEther. Store the results in variables balanceWeb3 and balanceEthers respectively.

Blockchain / Solidity

const Web3 = require('web3');
const web3 = new Web3('https://mainnet.infura.io/v3/YOUR_INFURA_PROJECT_ID');
const address = '0x742d35Cc6634C0532925a3b844Bc454e4438f44e';

const ethers = require('ethers');
const provider = new ethers.providers.JsonRpcProvider('https://mainnet.infura.io/v3/YOUR_INFURA_PROJECT_ID');

async function getBalances() {
    // Your code here
}

Need a hint?

Use await to get balances asynchronously. Convert wei to ether using the utilities from each library.

4

Print the Balances

Inside the getBalances function, print the balances with console.log using the exact format: Balance with Web3.js: {balanceWeb3} and Balance with ethers.js: {balanceEthers}. Then call the getBalances function.

Blockchain / Solidity

const Web3 = require('web3');
const web3 = new Web3('https://mainnet.infura.io/v3/YOUR_INFURA_PROJECT_ID');
const address = '0x742d35Cc6634C0532925a3b844Bc454e4438f44e';

const ethers = require('ethers');
const provider = new ethers.providers.JsonRpcProvider('https://mainnet.infura.io/v3/YOUR_INFURA_PROJECT_ID');

async function getBalances() {
    const balanceWei = await web3.eth.getBalance(address);
    const balanceWeb3 = web3.utils.fromWei(balanceWei, 'ether');
    const balanceBigNumber = await provider.getBalance(address);
    const balanceEthers = ethers.utils.formatEther(balanceBigNumber);
    // Print balances here
}

// Call the function here

Need a hint?

Use console.log with template strings to print the balances. Don't forget to call the getBalances function.