Free Blockchain CBDE Exam Questions

Become Blockchain Certified with updated CBDE exam questions and correct answers

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Total 102 Questions | Updated On: Nov 26, 2024

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Question 1

Unit-Testing on a local chain is important, because it helps you:

A : run tests quickly and especially for free, compared to continuous deployment on the MainNetwork. This way you save a lot of fees, time and costs

B : run tests in an environment where logging is activated. On the Main-Net you have no access to transaction logs and this is ultimately the information you need to debug your contracts

C : avoid regression bugs with contracts that are updated constantly on the main-net. Once you update a contract on the main-net, the address stays the same, but the code changes and this can have disastrous side-effects.

Answer: A

Question 2

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

A : l gas is consumed.

B : l remaining gas is returned

Answer: A

Question 3

When defining a new datatype:

A : best to use a contract with public storage variables, so it can be used like a class

B : 's best to use a struct, which is cheaper than deploying a new contract

C : 's not possible to generate new datatypes in Solidity

Answer: B

Question 4

To communicate with an Ethereum node via [removed]

A : library you use must make use of the JSON-RPC Interface of an Ethereum Node

B : t Implement the Ethereum Protocol to connect to other Ethereum Nodes.

C : t use Web3.js, which is closed source to communicate to other Ethereum Nodes.

Answer: A

Question 5

Multi-Line Comments in Solidity are:

A : rking with either // or ///

B : rking with /* comment */ or /** @.. natspec style */

C : t possible, all comments must be single-line

Answer: B

Page: 1 / 21

Total 102 Questions | Updated On: Nov 26, 2024

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