Free Blockchain CBDE Exam Dumps Questions & Answers

If you are starting a new ERC20 token:

• A.  it would be best to start from scratch, just looking at the required interface.
• B.  it is beneficial to copy and paste the already existing code from the Ethereum wiki and modify this until you like it.
• C.  best is to start with an audited implementation, for example from OpenZeppelin, in order to reuse already existing code.

It's possible to access the blockchain via an Ethereum Node:

• A.  only via JavaScript because there is the proprietary Web3.js library.
• B.  by any programming language, as long as it adheres to the JSON-RPC standard.

Assert is used:

• A.  to check internal states that should never happen.
• B.  to check input arguments from users.

Checking the balance of an address inside a loop of a smart contract constantly:

• A.  cost gas every time we check the balance.
• B.  doesn't cost any gas.

The nonce-field in a transaction is used:

• A.  to have an additional checksum for transactions.
• B.  to sum up all ethers sent from that address.
• C.  to protect against replay attacks.