Special variables are globally available variables and provides information about the blockchain. Following is the list of special variables:
| Sr.No. | Special Variable & Description |
|---|---|
| 1 | blockhash(uint blockNumber) returns (bytes32) Hash of the given block - only works for 256 most recent, excluding current, blocks. |
| 2 | block.coinbase (address payable) Current block miner's address. |
| 3 | block.difficulty (uint) current block difficulty. |
| 4 | block.gaslimit (uint) Current block gaslimit. |
| 5 | block.number (uint) Current block number. |
| 6 | block.timestamp Current block timestamp as seconds since unix epoch. |
| 7 | gasleft() returns (uint256) Remaining gas. |
| 8 | msg.data (bytes calldata) Complete calldata. |
| 9 | msg.sender (address payable) Sender of the message (current call). |
| 10 | msg.sig (bytes4) First four bytes of the calldata (i.e. function identifier) |
| 11 | msg.value (uint) Number of wei sent with the message. |
| 12 | now (uint) Current block timestamp (alias for block.timestamp). |
| 13 | tx.gasprice (uint) Gas price of the transaction. |
| 14 | tx.origin (address payable) Sender of the transaction (full call chain). |
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