ControlStructures contract

 create a File name called ControlStructures.sol

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

/**
 * @title ControlStructures
 * @dev Demonstrates control structures, conditionals, and custom errors in Solidity.
 */
contract ControlStructures {

    // Custom error for AfterHours condition
    error AfterHours(uint256 providedTime);

    /// @notice FizzBuzz logic using if/else conditions.
    /// @param _number Input number
    /// @return result String result based on divisibility
    function fizzBuzz(uint _number) public pure returns (string memory result) {
        if (_number % 3 == 0 && _number % 5 == 0) {
            return "FizzBuzz";
        } else if (_number % 3 == 0) {
            return "Fizz";
        } else if (_number % 5 == 0) {
            return "Buzz";
        } else {
            return "Splat";
        }
    }

    /// @notice Returns greetings or throws errors based on the time of day.
    /// @param _time A uint representing the time in 24-hour format (e.g., 1330 for 1:30 PM)
    /// @return message A string message if no error is triggered
    function doNotDisturb(uint _time) public pure returns (string memory message) {
        // 1️⃣ Panic if _time >= 2400
        if (_time >= 2400) {
            // "panic" is done via assert() failing intentionally
            assert(_time < 2400); 
        }

        // 2️⃣ After hours (before 8:00 or after 22:00)
        if (_time > 2200 || _time < 800) {
            revert AfterHours(_time);
        }

        // 3️⃣ Lunchtime 12:00 - 12:59
        if (_time >= 1200 && _time <= 1259) {
            revert("At lunch!");
        }

        // 4️⃣ Morning 8:00 - 11:59
        if (_time >= 800 && _time <= 1199) {
            return "Morning!";
        }

        // 5️⃣ Afternoon 13:00 - 17:59
        if (_time >= 1300 && _time <= 1799) {
            return "Afternoon!";
        }

        // 6️⃣ Evening 18:00 - 22:00
        if (_time >= 1800 && _time <= 2200) {
            return "Evening!";
        }

        // Just in case (should never reach here)
        return "Unknown time!";
    }
}