Ethereum Developer Web3.js, Ethers.js and Ethereum APIs

Question 1

What is the primary purpose of the ethers.js library in Ethereum development?

Accepted Answer

To interact with the Ethereum blockchain from JavaScript/TypeScript applications

Answer

To compile Solidity contracts into bytecode

Answer

To simulate Ethereum transactions off-chain

Answer

To deploy contracts to multiple EVM networks simultaneously

Question 2

What is a Provider in the context of ethers.js?

Accepted Answer

A read-only connection to an Ethereum node for querying blockchain data

Answer

An object that holds a private key for signing transactions

Answer

A class that compiles Solidity code at runtime

Answer

A middleware layer between the frontend and the contract

Question 3

What is a Signer in ethers.js?

Accepted Answer

An abstraction that holds a private key and can sign and send transactions

Answer

A function that verifies the validity of a signature

Answer

A node operator that validates blocks

Answer

A contract that manages key recovery

Question 4

What does ABI stand for in Ethereum development?

Accepted Answer

Application Binary Interface

Answer

Automated Blockchain Interpreter

Answer

Abstract Base Interface

Answer

Address Binding Index

Question 5

Which JSON-RPC method is used to get the ETH balance of an address on Ethereum?

Accepted Answer

eth_getBalance

Answer

eth_accounts

Answer

eth_getTransactionCount

Answer

eth_call

Question 6

What is MetaMask's primary role in a browser-based dApp?

Accepted Answer

An injected wallet that provides a Web3 provider and Signer to the dApp

Answer

A smart contract deployed on Ethereum to manage user sessions

Answer

A decentralized storage solution for dApp data

Answer

A compiler for Solidity code in the browser