Question No. 1

Address.call.value():

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

Bsends all the gas along and cascades exceptions.

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

Dsends the gas stipend of 2300 gas and cascades exceptions.

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Correct Answer: C

Question No. 2

Public Keys vs. Private Keys. Which statement is true?

AThe Public Key is for Signing Transactions, the Private Key must be given out to verify the signature.

BThe Private Key signs transactions, the Public Key can verify the signature.

CThe Private Key is to generate a Public Key. The Public Key can sign transactions, the address is here to verify the transactions.

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Correct Answer: B

Question No. 3

To get most out of the blockchain, it is best:

Ato use it for the whole business logic. It's always best to have everything in once place.

Bto use it only for things which need the benefits of the blockchain.

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Correct Answer: B

Question No. 4

If you need more fine-grained functionality than solidity offers out of the box:

Ayou can incorporate inline-assembly to get better controls.

Byou have to import pre-compiled assembly files which are then hard-copied into the bytecode of the compiled solidity file.

Cyou can use Viper, the experimental assembly like language specifically to offer more flexibility.

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Correct Answer: A

Question No. 5

In order to implement an ERC20 token contract, you'd need at least to implement the following functions and events in order to fulfill the interface requirements:

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

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

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Correct Answer: A

Free Blockchain CBDE Exam Actual Questions

The questions for CBDE were last updated On Jan 19, 2025