CBDE questions • Exam prepare

Exam contains 99 questions

Page 12 of 17

Question 67 🔥

Why is it important to follow the same Interfaces?

Which database solution meets these requirements?

A. Websites that try to interface with the Token would have to know the exact ABI. It is upfront clear how the interaction has to be with the standard Interfaces.

B. The Ethereum Foundation can easily validate the Tokens and approve any audits by following the standard interface.

Discussion of the question

Question 68 🔥

If contract MyContractA is derived from Contract MyContractB, then this would be the right syntax:

Which database solution meets these requirements?

A. contract MyContractA is MyContractB { … }

B. contract MyContractA inherit (MyContractB) {…}

C. contract MyContractA extends MyContractB {…}

D. contract MyContractB derives MyContractA {…}

Discussion of the question

Question 69 🔥

Inheritance is useful, because a contract that is derived from another contract can make use of:

Which database solution meets these requirements?

A. all public state variables and properties, public and internal functions and modifiers.

B. all public and private state variables, public, internal and external functions, but not modifiers

C. all public state variables and properties, public functions and modifiers, but not internal, external or private ones.

Discussion of the question

Question 70 🔥

Finish the sentence: The Library Web3.js is …:

Which database solution meets these requirements?

A. useful when developing distributed applications with HTML and JavaScript, because it already implements the abstraction of the JSON-RPC interface of Ethereum Nodes.

B. necessary when developing distributed applications with HTML and JavaScript, because the proprietary JSON-RPC interface of Ethereum Nodes is a closed source.

Discussion of the question

Question 71 🔥

When solidity is compiled then also Metadata is generated:

Which database solution meets these requirements?

A. 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.

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

C. 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.

Discussion of the question

Question 72 🔥

The difference between address.send() and address.transfer() is:

Which database solution meets these requirements?

A. .send returns a Boolean and .transfer throws an exception on error. Both just forward the gasstipend of 2300 gas and are considered safe against re-entrancy.

B. .send throws an exception and .transfer returns a Boolean on error. Both just forward the gasstipend of 2300 gas and considered safe against re-entrancy

C. .send returns a Boolean and .transfer throws an exception on error. .send is considered dangerous, because it sends all gas along, while .transfer only sends the gas stipend of 2300 gas along

D. .send and .transfer are both considered low-level functions which are dangerous, because they send all gas along. It's better to use address.call.value()() to control the gas-amount.

Discussion of the question

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blockchain CBDE

Exam contains 99 questions

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