Blockchain CBDE - BTA Certified Blockchain Developer - Ethereum

a function marked as pure can change the state, while a view function can only return static calls.

a function marked as view can never access state variables, while pure functions are here to return only one value.

a view function can access state variables, but not write to them. A Pure function cannot modify or read from state.

to bytecode that can't be understood by humans.

to bytecodes which are essentially opcodes running instruction by instruction.

it’s good to use a push over a pull method.

it’s good to use a push and a pull method to ensure that participants can get their money no matter the contract state. In addition to and pushing it should contain a withdraw method.

it's good to use only pull and no push method.

is great, because they often find bugs which weren't considered before.

is not good, because you might give out secrets.

string1 == string2

the internal function "str_compare(str1,str2)"

you can't directly compare two strings, but one method would be to hash both strings and compare the hashes.

bytes32(string1) == bytes32(string2)

the User.

contract A.

only via JavaScript because there is the proprietary Web3.js library.

by any programming language, as long as it adheres to the JSON-RPC standard.

all gas is consumed

all remaining gas is returned.

both are the same, just implemented in a different language.

with Go-Ethereum you get a real blockchain node where you can create your own local private network, connect to Test-Networks or the Main-Net, while with Ganache you get an in-memory blockchain simulation.

with Ganache you get a real blockchain node where you can connect to the Test-Networks Rinkeby and Ropsten.

it’s good to start with a local in-memory blockchain with unit tests but then deploy to the mainnet as rapidly as possible.

it's good to start with a local in-memory blockchain with unit-tests. Then, in the next step, debug and test the smart contract on a test-net like Ropsten or Rinkeby with beta customers to iron out last issues before deploying it to the main-net.

it's good to start with a test-net with beta-customers like on the Rinkeby or Ropsten testnet, before testing it locally on an in-memory blockchain simulation such as Ganache. Then deploy it to the main-net.