BTA Certified Blockchain Developer - Ethereum Questions and Answers
Question 9
Assert is used:
Options:
A.
to check internal states that should never happen.
B.
to check input arguments from users.
Answer:
A
Question 10
To get most out of the blockchain, it is best:
Options:
A.
to use it for the whole business logic. It’s always best to have everything in once place.
B.
to use it only for things which need the benefits of the blockchain.
Answer:
B
Question 11
The difference between address.send() and address.transfer() is:
Options:
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.
Answer:
A
Question 12
Which statement is true about the EVM?
Options:
A.
While the EVM is Sandboxed, it isn't as powerful as the Bitcoin Network, because it's not Turing Complete.
B.
The EVM can't access hardware layers or anything outside a blockchain node because it's sandboxed.
C.
The EVM is extremely powerful, turing complete and perfect for doing computational intensive things, because of the direct access to the graphics card.
