Free Practice Questions for Blockchain CBDE Exam

True

False

Integer, Boolean, Struct, Mapping and Enum.

Integer, Boolean, Enum and Addresses.

Integer, Boolean, Structs and Fixed Point Numbers.

To Protect the Public Keys by being cryptographically significant.

To Sign Transactions And To Derive an Address From.

To Generate An Address which can sign transactions.

can only be accessed during calls.

can be accessed during transactions and calls.

the Metadata contains the ABI Array, which defines the Interface to interact with the Smart Contract. Metadata can also contain the address of the smart contract when it gets deployed.

metadata contains the address, and the size of the smart contract. The ABI Array is generated externally upon deploying the smart contract.

the ABI array and the Metadata are not generated when solidity is compiled to bytecode, its generated by a migration software which deploys the smart contract on the blockchain.

Address.call() is used for calling other contracts using the scope of the called contract in terms of storage variables. Address.delegatecall() is used for libraries, which uses the storage variables of the contract who called. Libraries are a great way to re-use already existing code and delegatecall can make sure that no storage is used from the library, instead it looks like the code is directly copied into the calling contract.

Address.delegatecall() is used for calling other contracts using the scope of the called contract in terms of storage variables. Address.call() is used for libraries, which uses the storage variables of the contract who called. Libraries are a great way to re-use already existing code and call() can make sure that no storage is used from the library, instead it looks like the code is directly copied into the calling contract.

to bytecode that can't be understood by humans.

to bytecodes which are essentially opcodes running instruction by instruction.

to contribute to the box community which is the distributed file system for truffle.

to start with a pre-configured environment for most web-development needs.

to use tools that makes boxing of Dapps for different platforms very easy.

can't be split across multiple files, everything should be in one single file.

can be split across multiple files, but every contract must be in a file with the same name as the contract itself.

can be spread across multiple files. To import all contract from a file you can use "import 'myfile.sol'. To import Contract MyContract from myfile.sol you use "import {MyContract as SomeContract} from 'myfile.sol';".