Free Practice Questions for Blockchain CBDE Exam

True, but it's still good to use Ganache, or even a real private network for testing.

False, it's necessary to use Ganache or even a real private network for testing.

the library you use must make use of the JSON-RPC Interface of an Ethereum Node.

must Implement the Ethereum Protocol to connect to other Ethereum Nodes.

must use Web3.js, which is closed source to communicate to other Ethereum Nodes.

to run tests quickly and especially for free, compared to continuous deployment on the MainNetwork. This way you save a lot of fees, time and costs.

to run tests in an environment where logging is activated. On the Main-Net you have no access to transaction logs and this is ultimately the information you need to debug your contracts.

to avoid regression bugs with contracts that are updated constantly on the main-net. Once you update a contract on the main-net, the address stays the same, but the code changes and this can have disastrous side-effects.

ERC are here to define standards for the usage of Ethereum. EIP are here to improve the Ethereum Protocol itself.

ERC are here to propose new distributed applications on top of the Ethereum layer, while EIP are here to improve existing mining software.

ERC are an open platform to discuss continuous forking of the Ethereum platform. Successful forks are then incorporated in the EIP for further voting by the Ethereum Consortium.

great, because they cut the middle man, run on a trusted platform, apply logic to the blockchain where already economic assets are running and thus allow peer to peer trade.

an amazing way to create new applications. Those applications run entirely separated from other applications on the platform and allow for logical interactions. They can't access any funds to add an additional layer of trust.

a new way of applying logical operations for banks and big financial institutions. This way they can reduce the staff while operating at increased security.

2, because the decimal is truncated.

3, because it's always rounded.

2.5, because it's automatically converted into a float.

a function marked as pure can change the state, while a view function can only return static calls.

a function marked as view can never access state variables, while pure functions are here to return only one value.

a view function can access state variables, but not write to them. A Pure function cannot modify or read from state.

would be better, because it can reduce the amount of energy needed for mining.

would be worse, because it would increase the amount of energy needed for mining.

Tx.origin

Msg.sender

Wei, Finney, Szabo, Ether, Tether.

Finney, Szabo, Mether, Gwei.

Gwei, Szabo, Finney, Ether.