getBlockHash

Returns the block hash at a given height in the best chain.

Type

getBlockHash(height: number): Promise<string>

Parameters

height

A non-negative block height in the best chain.

Return Value

A Promise that resolves to the block hash (64-character hex string) at that height.

Description

Returns the hash of the block at the given height. Round-trips with getBlockHeight: getBlockHash(await getBlockHeight(hash)) yields the same hash for blocks in the best chain.

Inside smart contracts (InnerComputer)

• Negative heights invalidate the evaluation.
• Heights greater than the current tip (future blocks) invalidate the evaluation.

See Contract – Querying.

Example

const counter = await computer.new(Counter, [])
await computer.faucet(1e8)
const txId = counter._id.slice(0, 64)
const blockHash = await computer.txIdToBlockHash(txId)
const height = await computer.getBlockHeight(blockHash)

const hashFromHeight = await computer.getBlockHash(height)
// hashFromHeight === blockHash