Blockchain Developer FREE Blockchain Developer Smart Contract Development Questions and Answers 2

Question 1

What is the primary purpose of the 'require' statement in Solidity smart contracts?

Accepted Answer

To validate conditions and revert the transaction if not met

Answer

To import external libraries

Answer

To declare state variables

Answer

To define function visibility

Question 2

Which design pattern is used to allow upgrading smart contract logic while preserving stored data?

Accepted Answer

Proxy pattern

Answer

Factory pattern

Answer

Observer pattern

Answer

Singleton pattern

Question 3

What happens when a smart contract function marked as 'view' attempts to modify state?

Accepted Answer

The compiler throws an error

Answer

The modification is silently ignored

Answer

The transaction reverts at runtime

Answer

The function executes normally

Question 4

In Solidity, what is the maximum size of a deployed smart contract's bytecode on Ethereum mainnet?

Accepted Answer

24,576 bytes

Answer

16,384 bytes

Answer

32,768 bytes

Answer

49,152 bytes

Question 5

Which vulnerability occurs when a contract makes an external call before updating its own state?

Accepted Answer

Reentrancy attack

Answer

Integer overflow

Answer

Front-running

Answer

Access control bypass

Question 6

What is the purpose of the 'indexed' keyword for event parameters in Solidity?

Accepted Answer

It allows the parameter to be used as a filter when searching logs

Answer

It stores the parameter in contract storage

Answer

It makes the parameter immutable

Answer

It encrypts the parameter value