Constants in Solidity

Constants are variables that cannot be modified.

Their value is hard coded and using constants can save gas cost.

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

contract Constants {
     // coding convention to uppercase constant variables
     address public constant MY_ADDRESS = 0x777788889999AaAAbBbbCcccddDdeeeEfFFfCcCc;
     uint256 public constant MY_UINT= 123;
}