CBDH CBDH Smart Contract Development

Question 1

In Hyperledger Fabric, what language is primarily used to write chaincode (smart contracts)?

Accepted Answer

Go

Answer

Hyperledger Fabric supports chaincode written in Go, JavaScript (Node.js), and Java, with Go being the most commonly used language.

Question 2

Which interface must a Fabric chaincode implement to be valid?

Accepted Answer

Chaincode

Answer

All Hyperledger Fabric chaincode must implement the Chaincode interface, which requires Init and Invoke methods.

Question 3

What does the `stub.PutState(key, value)` function do in Fabric chaincode?

Accepted Answer

Writes or updates a key-value pair on the ledger

Answer

PutState writes or updates a key-value pair in the world state ledger during chaincode execution.

Question 4

Which chaincode function is invoked when the chaincode is first instantiated or upgraded?

Accepted Answer

Init()

Answer

The Init() function is called during chaincode instantiation or upgrade, allowing initialization of ledger state.

Question 5

What is the purpose of `stub.GetState(key)` in Hyperledger Fabric chaincode?

Accepted Answer

Retrieves the value associated with a key from the world state

Answer

GetState retrieves the byte-array value associated with the specified key from the channel's world state.

CBDH - Certified Blockchain Developer Hyperledger Practice Test