Block and transaction global variables

Solidity provides access to a few global variables that are not declared within contracts but are accessible from code within contracts. Contracts cannot access the ledger directly. A ledger is maintained by miners only; however Solidity provides some information about the current transaction and block to contracts so that they can utilize them. Solidity provides both block-as well as transaction-related variables.

The following code illustratesexamples of using global transaction, block, and message variables:

Transaction and message global variables

The following is a list of global variables along with their data types and a description provided as a ready reference:

Variable name	Description
block.coinbase (address)	Same as etherbase. Refers to the miner's address.
block.difficulty (uint)	Difficulty level of current block.
block.gaslimit (uint)	Gas limit for current block.
block.number (uint)	Block number in sequence.
block.timestamp (uint)	Time when block was...