How to pass bytes4 to mapping?

Question

I'm trying to pass bytes4 type to mapping but all I have got is an error saying:
**ParserError: Expected identifier but got '='**

bytes4 example = 0x11030330;
mapping(bytes4 => address) facets;
facets[example] = 0xaE036c65C649172b43ef7156b009c6221B596B8b;

Answer 1

This is an example how to do it:

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

contract Bytes4InMapping {
    mapping(bytes4 => address) public facets;

    function addValueInsideMapping(bytes4 _key) public {
        facets[_key] = msg.sender;
    }
}