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1_WriteInTheBlockchain.sol

// SPDX-License-Identifier: MIT

pragma solidity >=0.8.0 <0.9.0;

contract RandomTestContract{
    string text;

    function write(string calldata _text) public{
        text = _text;
    }

    function read() public view returns(string memory){
        return text;
    }
}

2_RandomToDoList.sol

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.6;

contract RandomToDoList {
    
    struct Task {
        uint id;
        string title;
        address owner;
    }
    
    Task[] tasks;

    function getTasksLen() internal view returns(uint){
        return tasks.length;
    } 

    function isOwner(address _owner) internal view returns(bool){
        if(_owner == msg.sender || _owner == tx.origin){
            return true;
        }
        revert("You are not the owner");
    }
    
    
    function createTask(string memory _name) public {
        uint nextId = getTasksLen();
        tasks.push(Task(nextId, _name, msg.sender));
    }

    function readTask(uint _id) public view returns (uint, string memory, address) {
        // if(isOwner(tasks[_id].owner)){
            return (tasks[_id].id, tasks[_id].title, tasks[_id].owner);
        // }
        // return (0, "You are not the owner", msg.sender);
    }
    
    
    function updateTask(uint _id, string memory _title) public {
        if(isOwner(tasks[_id].owner)){
            tasks[_id].title = _title;
        }
    }
    
    
    function deleteTask(uint _id) public {
        if(isOwner(tasks[_id].owner)){
            delete tasks[_id];
        }
    }
    
}