solidity - Invalid type for argument in function call. Invalid implicit conversion from address to address payable requested - typeerror

Question

I am trying to give address as payable but I am getting error at msg.sender and address(_author).transfer(msg.value) . it was showing like Invalid type for argument in function call. Invalid implicit conversion from address to address payable requested. i tried many ways to solve every time i replace the same error. before adding payable to author it was fine, but when added payable to author then it started getting error. In both, msg.sender and msg.value
pragma solidity >=0.4.0 <0.9.0;
contract SocialNetwork {
string public name;
uint public postCount = 0;
mapping(uint => Post) public posts;
struct Post {
uint id;
string content;
uint tipAmount;
address payable author;
}
event PostCreated(
uint id,
string content,
uint tipAmount,
address payable author
);
event PostTipped(
uint id,
string content,
uint tipAmount,
address payable author
);
constructor() public {
name = "Yash university Social Network";
}
function createPost(string memory _content) public {
//REquire Valid content
require(bytes(_content).length > 0);
// InCREMENT the post count
postCount ++;
// Create the post
posts[postCount] = Post(postCount, _content, 0, msg.sender);
// Trigger event
emit PostCreated(postCount, _content, 0, msg.sender);
}
function tipPost(uint _id) public payable {
//fetch the post
Post memory _post = posts[_id];
//fetch the author
address payable _author = _post.author;
//pay the author
address(_author).transfer(msg.value);
//increment the tip post
_post.tipAmount = _post.tipAmount + msg.value;
//update the post
posts[_id] = _post;
//Trigger an event
emit PostTipped(postCount, _post.content, _post.tipAmount, _author);
}
}

Answer 1

You have a few issues in your code:
1- in the Post struct, you defined address as payable:
struct Post {
uint id;
string content;
uint tipAmount;
address payable author;
}
But when you are creating a post, you are passing msg.sender which has address type. Before v0.8.0 msg.sender was payable but since than you have to cast it as payable(msgs.sender). it should be:
function createPost(string memory _content) public {
require(bytes(_content).length > 0);
postCount ++;
posts[postCount] = Post(postCount, _content, 0, payable(msg.sender));
emit PostCreated(postCount, _content, 0, payable(msg.sender));
}
2- in tipPost function you are getting payable address
address payable _author = _post.author;
but then you are casting it with address. In solidity address and payable address are two different things. send and transfer are only available to the payable address type. You dont need this:
address(_author).transfer(msg.value);
instead just
_author.transfer(msg.value);