The value of a constant cannot change through reassignment, and it can't be redeclared after compile time. In solidity, a state variable can be declared as constant. It does not allow reassignment to blockchain data (for example, this .balance, block.blockhash), or execution data (tx.gasprice), or make calls to external contracts.
The following table out the solidity global variables and their built-in functions:
|
Global variables / functions |
Description |
|
msg.sender(address) |
msg.sender is the address currently interacting with the contract call message. |
|
msg.data(bytes) |
msg.data is the address currently interacting with the contract complete call. The data is in bytes. |
|
msg.value(unit) ... |
