First miniblog contract

miniblog.sol

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

contract MiniBlog {
    uint256 public latestPostId = 0;
    
    struct User {
        string username;
        string bio;
        uint256[] postIds;
    }
    
    struct Post {
        string title;
        string content;
        address author;
        uint256 created;
    }
    
    mapping (address => User) public users;
    mapping (uint256 => Post) public posts;
    
    event NewPost(address indexed author, uint256 postId, string title);
    
    function createPost(string memory title, string memory content) public {
        latestPostId++;
        
        posts[latestPostId] = Post(title, content, msg.sender, block.timestamp);
        users[msg.sender].postIds.push(latestPostId);
        
        emit NewPost(msg.sender, latestPostId, title);
    }
    
    function modifyPostTitle(uint256 postId, string memory title) public {
        require(msg.sender == posts[postId].author, "Only the author can modify");
        
        posts[postId].title = title;
    }
    
        function modifyPostContent(uint256 postId, string memory content) public {
        require(msg.sender == posts[postId].author, "Only the author can modify");
        
        posts[postId].content = content;
    }
    
    function updateUsername(string memory username) public {
        users[msg.sender].username = username;
    }
    
        function updateBio(string memory bio) public {
        users[msg.sender].bio = bio;
    }
    
    function getPostIdsByAuthor(address author) public view returns (uint256[] memory) {
        return users[author].postIds;
    }
    
    function getPostById(uint256 postId) public view returns (string memory title, string memory content) {
        title = posts[postId].title;
        content = posts[postId].content;
    } 
}