Activity_4.sol

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.31;

contract Activity_4 {
    /**
        Temperature Checker
        Make a function that will tell if the temperature is freezing point or boiling point.
        Grade Evaluator
        Make a function that will return a grade based on a score.
            90 and above → “A”


        80–89 → “B”


        70–79 → “C”


        Below 70 → “F”
    **/
    function tempChecker(uint temp) public pure returns (string memory) {
        if (temp >= 90) {
            return "A";
        } else if (temp < 90 && temp >= 80) {
            return "B";
        } else if (temp < 80 && temp >= 70) {   
            return "C";
        } else {
            return "F";
        }
    } 
    /**
    Speed Checker
    Make a function that checks if a driver is overspeeding.
    Note: 100 is speed limit
    **/

    function speedChecker(uint kph) public pure returns (string memory) {
        uint MAX_LIMIT = 100;
        if (kph > MAX_LIMIT) {
            return 'Overspeeding';
        }
        return 'Not Overspeeding';
    } 

    /**
        Age-Based Access
        Make a function that checks if a person can enter a restricted zone.
        Notes:
            13 - not allowed
            13 - 17 - required with guardian 
            18 - allowed
    */
    function ageRestriction(uint age) public pure returns (string memory) {
        if (age >= 18) {
            return 'Allowed';
        } else if (age >= 13 && age <= 17) {
            return 'Requires a guardian';
        }
        return 'Not allowed';
    }

    /**
        Sum 1 to N
        Make a function that will compute the sum of numbers from 1 to N.
        Example: 5 → 1 + 2 + 3 + 4 + 5 = 15
    */

    function sum1ToN(uint n) public pure returns (uint sum) {
        for (uint i = 1; i <= n; i++) { 
            sum += i;
        }
        return sum;
    }
    

    /**
        Even Numbers Printer 
        Make a function that adds up all even numbers up to N.
        Example: Input: 10 → Output: 2 + 4 + 6 + 8 + 10 = 30 
    */

    function printEventNumbers(uint number) public pure returns (uint) {
        uint sum = 0;
        for (uint i = 1; i <= number; i++) {
            if (i % 2 == 0) {
                sum += i;
            }
        }
        return sum;
    }

}