CBDE questions • Exam prepare

Exam contains 99 questions

Page 13 of 17

Question 73 🔥

All low-level functions on the address, so address.send(), address.call.valueQQ, address.callcode and address.delegatecall:

Which database solution meets these requirements?

A. are interrupting execution on error, because they throw an exception.

B. continuing execution on error silently, which is the reason why they are so dangerous.

C. returning Booleans to indicate an error during execution.

D. .send() throws an exception, while the other functions are returning Booleans during execution to indicate an error.

Discussion of the question

Question 74 🔥

When using assert to check invariants and it evaluates to false:

Which database solution meets these requirements?

A. all gas is consumed.

B. all remaining gas is returned.

Discussion of the question

Question 75 🔥

When using require to check input parameters and it evaluates to false:

Which database solution meets these requirements?

A. all gas is consumed

B. all remaining gas is returned.

Discussion of the question

Question 76 🔥

To send ether to a contract without a function call:

Which database solution meets these requirements?

A. 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.

B. either a fallback function which is payable exists, or no fallback function at all exists.

C. you cannot send ether to a contract without explicitly calling a function. The fallback function can never receive ether.

Discussion of the question

Question 77 🔥

Using selfdestruct(beneficiary) with the beneficiary being a contract without a payable fallback function:

Which database solution meets these requirements?

A. will throw an exception, because the fallback function is non-payable and thus cannot receive ether.

B. it's impossible to secure a contract against receiving ether, because selfdestruct will always send ether to the address in the argument. This is a design decision of the Ethereum platform.

C. selfdestruct doesn't send anything to a contract, it just re-assigns the owner of the contract to a new person. Sending ether must be done outside of selfdestruct.

Discussion of the question

Question 78 🔥

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

Which database solution meets these requirements?

A. you can incorporate inline-assembly to get better controls.

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

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

Discussion of the question

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Exam contains 99 questions

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