Blockchain BTA Certified Blockchain Developer - Ethereum - CBDE Exam Practice Test

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

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

A. totalSupply(), balanceOf(address), allowance(address,address), transfer(address,uint256), approve(address,uint256), transferFrom(address,address,uint256). Events: Transfer(address,address,uint256), Approval(address,address,uint256)

B. name(), symbol(), totalSupply(), balanceOf(address), ownerOf(uint26),approve(address,uint256), takeOwnership(uint256),transfer(address,uint256),Events: Transfer(address,address,uint256), Approval(address,address,uint256)

A. all gas is consumed

B. all remaining gas is returned.

A. you can't directly compare two strings, but one method would be to hash both strings and compare the hashes.

B. string1 == string2

C. the internal function "str_compare(str1,str2)"

D. bytes32(string1) == bytes32(string2)

A. contract MyContractA is MyContractB { ... }

B. contract MyContractA inherit (MyContractB) {...}

C. contract MyContractB derives MyContractA {...}

D. contract MyContractA extends MyContractB {...}

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

B. working with either // or ///

C. not possible, all comments must be single-line.

A. to check input arguments from users.

B. to check internal states that should never happen.

A. 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.

B. 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.

C. 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.

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

B. 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.

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