PHP Language Fundamentals Mastery Hub: The Industry Foundati

In the context of modern PHP development as emphasized in "The Complete PHP Syntax & Basics Course 2026," which of the following is the most idiomatic way to declare a variable that can hold either a string or an integer, ensuring type safety and clarity?

Considering the course's focus on "The Industry Foundation," when working with arrays in PHP, which approach offers the most significant performance advantage for large datasets when frequent lookups by key are required, and why?

In "The Complete PHP Syntax & Basics Course 2026," the emphasis on robust error handling is crucial. If a function might throw an exception, what is the most appropriate and modern PHP construct to gracefully handle potential errors and prevent application crashes?