Web3.js vs ethers.js in Blockchain / Solidity - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a new instance of Web3 using a provider.

Blockchain / Solidity

const Web3 = require('web3');
const web3 = new Web3([1]);

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Awindow.ethereum

Bethers.providers.JsonRpcProvider

Cnew ethers.providers.Web3Provider()

Dweb3.eth

Attempts:

3 left

💡 Hint

Common Mistakes

Using ethers.js provider instead of Web3.js provider.

In Web3.js, you create a new instance by passing a provider like window.ethereum.

2fill in blank

medium

Complete the code to create a new ethers.js provider connected to a JSON RPC URL.

Blockchain / Solidity

const { ethers } = require('ethers');
const provider = new ethers.providers.[1]('https://mainnet.infura.io/v3/YOUR-PROJECT-ID');

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AWeb3Provider

BAlchemyProvider

CJsonRpcProvider

DInfuraProvider

Attempts:

3 left

💡 Hint

Common Mistakes

Using Web3Provider which expects a web3 provider object.

Use JsonRpcProvider to connect to a JSON RPC URL in ethers.js.

3fill in blank

hard

Fix the error in the code to get the balance of an address using ethers.js.

Blockchain / Solidity

const balance = await provider.getBalance([1]);

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A12345

B'0x742d35Cc6634C0532925a3b844Bc454e4438f44e'

Cprovider.address

Dethers.utils.getAddress()

Attempts:

3 left

💡 Hint

Common Mistakes

Passing a number or invalid object instead of a string address.

The getBalance method requires a valid Ethereum address as a string.

4fill in blank

hard

Fill both blanks to create a contract instance using ethers.js with ABI and address.

Blockchain / Solidity

const contract = new ethers.Contract([1], [2], provider);

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A'0x1234567890abcdef1234567890abcdef12345678'

Babi

Caddress

Dprovider

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping address and ABI positions.

The first argument is the contract address as a string, the second is the ABI array.

5fill in blank

hard

Fill all three blanks to send a transaction using Web3.js with from address, to address, and value.

Blockchain / Solidity

web3.eth.sendTransaction({ from: [1], to: [2], value: [3] });

Drag options to blanks, or click blank then click option'

A'0xYourAddressHere'

B'0xRecipientAddressHere'

C'1000000000000000000'

D'someValue'

Attempts:

3 left

💡 Hint

Common Mistakes

Using numbers instead of strings for addresses or value.

Use string addresses for from and to, and a string of wei for value.