Activity_Day10.sol

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

contract Activity_5 {

    /**
    Activity 1
    Create a fixed-size array of length 3 called favoriteNumbers.
    Add a function setNumber(uint index, uint value) that updates a number at a given index.
    Add another function getNumber(uint index) that returns the value at that index.
    */
    uint256[3] favoriteNumbers;
    function setNumber(uint256 a, uint256 b, uint256 c) public { 
        favoriteNumbers[0] = a;
        favoriteNumbers[1] = b;
        favoriteNumbers[2] = c;
    }

    function getNumber(uint index) public view returns (uint) {
        return favoriteNumbers[index];
    }

    /**
    Activity 2: Dynamic Array Practice
    Instructions:
    Declare a dynamic array named scores.
    Add a function addScore(uint value) to push new values.
    Add a function removeLast() to pop the last value.
    Add a function getScore(uint index) to get a score by position
    Add a function getTotalScores() that returns scores.length.
    */
    uint[] scores;
    function addScores(uint value) public {
        scores.push(value);
    }

    function removeLast() public {
        scores.pop();
    }

    function getScore(uint index) public view returns (uint) {
        return scores[index];
    }

    function getTotalScores() public view returns (uint sum) {
        for (uint i=0; i < scores.length;i++) {
            sum += scores[i];
        }
        return sum;
    }


    /**
    Activity 3: Wallet Balances
    Instructions:
    Create a mapping mapping(address => uint) public balances;
    Add a function deposit(uint amount) that increases msg.sender’s balance.
    Add a function getBalance(address user) that returns their balance.
    Add a function resetMyBalance() that resets your own balance to 0.
    */

    mapping(address => uint) public balances;
    function deposit(uint amount) public {
        balances[msg.sender] += amount;
    }
    function getBalance(address user) public view returns (uint) {
        return balances[user];
    }
    function resetMyBalance() public {
        balances[msg.sender] = 0;
    }

    /**
    Activity4: Struct + Array
    Instructions:
    Reuse the Student struct.
    Declare Student[] public students
    Add a function addStudent(string memory _name, uint _age, bool _enrolled) that pushes a new student to the array.
    Add a function getStudent(uint index) that returns a specific student.
    Add a function getTotalStudents() that returns the array length.
    */
    struct Student {
        string name;
        uint age;
    }
    Student[] public students;

    function addStudent(string memory name, uint age) public {
        Student memory newStudent = Student({
            name: name,
            age: age
        });
        students.push(newStudent);
    }
 
    function getStudent(uint index) public view returns (string memory, uint) {
        Student memory student = students[index];
        return (student.name, student.age);
    }

    function getTotalStudents() public view returns (uint) {
        return students.length;
    }

}