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

While the EVM is Sandboxed, it isn't as powerful as the Bitcoin Network, because it's not Turing Complete.

The EVM can't access hardware layers or anything outside a blockchain node because it's sandboxed.

The EVM is extremely powerful, turing complete and perfect for doing computational intensive things, because of the direct access to the graphics card.

both are the same, just implemented in a different language.

with Go-Ethereum you get a real blockchain node where you can create your own local private network, connect to Test-Networks or the Main-Net, while with Ganache you get an in-memory blockchain simulation.

with Ganache you get a real blockchain node where you can connect to the Test-Networks Rinkeby and Ropsten.

a list of transactions as well as uncles is incorporated in the block. All gas that is used during those transactions is added to the miners' balance. Also, the block reward is added to the miner. Then the same transactions are run again by every participating node in the network to achieve consensus.

a list of transactions is incorporated in that block. Gas used during the execution is attached to the executing contracts while the block reward is automatically spread across the mining pool to ensure a fair spread. Consensus is reached by a special form of hash code.

it would be best to start from scratch, just looking at the required interface.

it is beneficial to copy and paste the already existing code from the Ethereum wiki and modify this until you like it.

best is to start with an audited implementation, for example from OpenZeppelin, in order to reuse already existing code.

contract MyContractA is MyContractB { … }

contract MyContractA inherit (MyContractB) {…}

contract MyContractA extends MyContractB {…}

contract MyContractB derives MyContractA {…}

are stored on chain and are a great way to get a return value when a contract calls another contract.

are stored in something like a side-chain and cannot be accessed by contracts.

are used primarily for debugging exceptions in solidity.

sends the gas stipend of 2300 gas and returns a false on error.

sends all the gas along and cascades exceptions.

sends all the gas along and returns a false on error.

sends the gas stipend of 2300 gas and cascades exceptions.

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.

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.

safe against reentrancy because of the small gas stipend of 2300 gas.

dangerous because they send all gas along, it's better to use address.call.value()().