CBDE Exam Dumps - BTA Certified Blockchain Developer - Ethereum

you should follow the checks-effects-interactions pattern and avoid state changes after the call.

you should follow the effects-checks-interactions pattern and avoid state changes before the call.

you should follow the checks-effects-interactions pattern, which is only necessary when you do calls to contracts where a direct contract call is not possible.

works across all compilers and platforms the same way.

is generally possible, but currently works only in Remix, but doesn't work in Truffle.

can never become a mining node.

can always become a mining node.

can become a mining node, depending if the implementation has the functionality implemented.

Java, C++, Solidity and JavaScript, because the Ethereum Blockchain is completely language agnostic and cross compilers exist for every major language.

Solidity, Viper, LLL and Serpent, because those are high level languages that are compiled down to bytecode.

Solidity and JavaScript, because those are the official first implementations for Distributed applications and the Blockchain supports those languages fully.

by the miner nodes which make sure that a transaction is valid.

by every single node in the blockchain network executing the same transaction.

by a cryptographic secure signature algorithm called ECDSA which makes sure that cheating is impossible.

working with either // or ///

working with /* comment */ or /** @.. natspec style */

not possible, all comments must be multi-line.

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.

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.

always having the same signature.

having a different signature because of the nonce which changes upon every transaction.

1 Ether = 10^18 wei, 10^9 Gwei, 10^3 Finney

1 Ether = 10^19 wei, 10^13 Gwei, 10^3 Finney

1 Ether = 10^16 wei, 10^13 Gwei, 10^3 Finney

1 Ether = 10^18 wei, 10^6 Gwei, 10^6 Finney

is used to communicate between blockchain nodes.

is used to ensure safe communication between miners.

is a mean of dumping the blockchain data in a so-called consensus export.

is used to communicate between the blockchain node and externally running applications.

Keccack256 while internally to hash values it's easy to use the Dagger-Hashimoto to create a meaningful hash.

the Dagger-Hashimoto hashing while internally the EVM uses SHA256 which is an alias for Keccack256.

the Dagger-Hashimoto hashing while internally the EVM uses Keccack256 which is almost similar to SHA256, but has a different padding so produces different hashes.