Have you worked with functions that are defined anonymously inside and called directly?

Yes, PHP has anonymous functions (closures) that can be defined without a name and invoked immediately. These functions are often used for one-time code execution or as arguments to other functions.

Example of an anonymous function invoked immediately:

(function() {
    echo "Hello from anonymous function!";
})();

Here, the function is defined and immediately called thanks to the parentheses at the end. This is useful for isolating code or creating a local context without polluting the global namespace.