continue statements that are targeting switch statements. In PHP 7.3 and later, such usages are deprecated and will emit an E_WARNING, since they are most likely the result of a programming mistake.
continue statements are equivalent to break, that is, they end the execution of the current switch structure.
continue statements behave as continue 2 in PHP, that is, they take the execution to a higher level control structure (for example, the next iteration of an outer loop).
See continue (php.net), break (php.net), and switch (php.net) for details.