Cryptocurrency Smart Contracts and Token Standards

Question 1

What is a smart contract?

Accepted Answer

A self-executing program stored on a blockchain that runs when conditions are met

Answer

A smart contract is a self-executing program on a blockchain that automatically enforces and executes terms when predefined conditions are fulfilled.

Question 2

Which programming language is most widely used to write Ethereum smart contracts?

Accepted Answer

Solidity

Answer

Solidity is Ethereum's primary programming language for writing smart contracts, with syntax influenced by JavaScript and C++.

Question 3

What is the Ethereum Virtual Machine (EVM)?

Accepted Answer

The decentralized computation engine that executes smart contracts on Ethereum

Answer

The EVM is the runtime environment that executes smart contract bytecode across all Ethereum nodes in a deterministic way.

Question 4

What is 'gas' in the context of Ethereum smart contracts?

Accepted Answer

A unit measuring computational effort required to execute operations on Ethereum

Answer

Gas measures the computational work needed to execute operations on Ethereum, preventing spam and incentivizing validators.

Question 5

What is a reentrancy attack in smart contracts?

Accepted Answer

An exploit where a malicious contract repeatedly calls a vulnerable contract before the first call completes

Answer

A reentrancy attack exploits a vulnerability where a contract calls an external contract before updating its own state, enabling recursive fund draining.

Cryptocurrency Practice Test

Cryptocurrency Practice Test

Cryptocurrency Smart Contracts and Token Standards