todo.sol

pragma solidity ^0.5.1;

// Creating a contract
contract Bloc{
	
// Defining a structure to
// store a task
struct Task
{
string task;
bool isDone;
}

mapping (address => Task[]) private Users;
	
// Defining function to add a task
function addTask(string calldata _task) external
{
Users[msg.sender].push(Task({
	task:_task,
	isDone:false
	}));
}

// Defining a function to get details of a task
function getTask(uint _taskIndex) external view returns (Task memory)
{
Task storage task = Users[msg.sender][_taskIndex];
return task;
}

// Defining a function to update status of a task
function updateStatus(uint256 _taskIndex,bool _status) external
{
Users[msg.sender][_taskIndex].isDone = _status;
}

// Defining a function to delete a task
function deleteTask(uint256 _taskIndex) external
{
delete Users[msg.sender][_taskIndex];
}

// Defining a function to get task count.
function getTaskCount() external view returns (uint256)
{
return Users[msg.sender].length;
}
}