Blockchain Developer Certification Practice

What happens to function arguments of reference types declared with the memory keyword?

1. They are stored permanently on the blockchain

2. They are not stored and are lost after function execution

3. They are temporarily held and do not cost gas

4. They are saved in a stack

The correct answer is: They are temporarily held and do not cost gas

The correct answer indicates that function arguments of reference types declared with the memory keyword are temporarily held and do not cost gas. In the context of smart contracts, particularly in Ethereum's Solidity language, the memory keyword signifies that the data stored is ephemeral, meaning it exists only for the duration of the function call. When variables are marked as memory, they are stored in a temporary storage area during the execution of the function. This is crucial because it allows for temporary data manipulation without impacting the overall state of the contract or incurring a gas cost associated with permanent storage. This makes memory variables ideal for large structures or arrays that do not need to persist after the function call is complete. In contrast, if arguments were stored permanently on the blockchain, it would lead to higher transaction costs due to the gas fees associated with storage. Also, while arguments that are lost after function execution accurately describe the transient nature of memory variables, the function arguments themselves do not mean they hold a zero-cost implication regarding gas. Likewise, stating that they are saved in a stack does not capture the essence of how memory variables operate within the context of Ethereum, since the stack is used for different purposes in function execution. Thus, the nature of temporary storage and zero gas cost for