Variables in Solidity

There are 3 types of variables in Solidity

• local

  • declare inside a function
  • not stored on the blockchain

• state

  • declared outside a function
  • stored on the blockchain

• global (provides information about the blockchain)
  
  

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.24;

contract Variables {
     // State variables are stored on the blockchain.
     string public text = "Hello";
     uint256 public num = 123;

     function doSomething() public { 
          // Local variables are not saved to the blockchain.
          uint256 i = 456;

          // Here are some global variables
          uint256 timestamp = block.timestamp; // current block timestamp
          address sender = msg.sender; // address of the caller
     }
}