Pass the Blockchain Blockchain Developer - Ethereum CBDE Questions and answers with CertsForce

it's good to inform users about the updates via a newsletter.

it's good to have the ability to pause a contract in order to manage the money at risk.

Ethereum doesn't upgrade the platform. It's fixed and final.

are changing their address every time a Transaction is sent because of the nonce.

are keeping their address, but on the blockchain a nonce is increased every time they send a transaction to avoid replay attacks.

a fallback function must be declared and it must be made payable. If there is no fallback function or the fallback function is not payable it will throw an exception.

either a fallback function which is payable exists, or no fallback function at all exists.

you cannot send ether to a contract without explicitly calling a function. The fallback function can never receive ether.

you should capitalize function names, events and contract names, to avoid confusion with JavaScript. You should use Tabs to indentation and a maximum of 80 characters per line.

contract names should be capitalized, while functions should be mixedCase. You should use 4 spaces as indentation and a maximum of 79 (or 99) characters per line.

contract should be mixedCase, as well as function names. Events should be capitalized. 2 spaces should be used as indentation and a maximum of 120 characters per line.

PoW is computationally intensive which requires lots of energy. On the other hand, miners earn straightforward a reward for mining a block and incorporating transactions.

PoW is better than PoS, because with PoS we increase the amount of energy spent on the network.

PoS is mining with specialized new hardware that has to be purchased with a stack of Ether in the network. Hence the Name: Proof of Stake, which derives from Stack.

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.

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.

will throw an exception, because the fallback function is non-payable and thus cannot receive ether.

it's impossible to secure a contract against receiving ether, because selfdestruct will always send ether to the address in the argument. This is a design decision of the Ethereum platform.

selfdestruct doesn't send anything to a contract, it just re-assigns the owner of the contract to a new person. Sending ether must be done outside of selfdestruct.

is a framework that helps developers with Testing, Deployment and Management of Smart Contracts and Distributed Applications.

is a library that helps developers to connect to Ethereum nodes, because it abstracts the JSONRPC interface.

is a framework for Java, similar to Web3.js for JavaScript. It's a great way to develop distributed Java enterprise applications.

Wei, Finney, Szabo, Ether, Tether.

Finney, Szabo, Mether, Gwei.

Gwei, Szabo, Finney, Ether.