What is the purpose of the exit() function in PHP?

The purpose of the exit() function in PHP is to terminate the current script effectively. When you call exit(), it immediately stops the execution of the script at that point. This is particularly useful in scenarios where you need to halt the script under certain conditions, such as after displaying an error message or when a specific condition is not met.

Using exit() can be vital in ensuring that no subsequent code is executed, which could lead to unexpected behaviors or security issues. It can also accept a message as an argument, which will be output to the user before termination, or an integer value that can be used as a status code indicating how the script ended.

In this context, the other options do not accurately represent the functionality of the exit() function. It neither pauses the script, nor redirects to another page, nor is it primarily used for outputting messages to the screen. Each of these functionalities corresponds to different functions or mechanisms in PHP, solidifying exit() as specifically designed for ending script execution.