Ethereum Developer Solidity Smart Contract Development

Question 1

Which Solidity keyword is used to declare a function that cannot modify contract state?

Accepted Answer

view

Answer

The `view` keyword declares a function that can read but not modify state variables.

Question 2

What is the purpose of the `payable` keyword in a Solidity function?

Accepted Answer

It allows the function to receive Ether

Answer

The `payable` keyword allows a function to receive Ether as part of a transaction.

Question 3

Which Solidity data type is used to store Ethereum addresses?

Accepted Answer

address

Answer

The `address` type is a 20-byte value specifically designed to hold Ethereum addresses.

Question 4

What does the `require` statement do in Solidity when its condition is false?

Accepted Answer

Reverts the transaction and refunds unused gas

Answer

When `require` fails, it reverts all state changes and refunds the remaining gas to the caller.

Question 5

In Solidity, what is a `mapping`?

Accepted Answer

A hash table that maps keys to values

Answer

A `mapping` in Solidity is a hash table that maps keys of one type to values of another type.

Ethereum Developer Practice Test