Variables (Solidity Code Example)

There are 3 types of variables in Solidity

• local
  • declared 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 ^0.8.26;

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
    }
}