What are the advantages and disadvantages of using sleep, meta-refresh, or Ajax calls to slow down a loop in PHP?

When dealing with a loop in PHP that needs to be slowed down, there are a few options such as using sleep, meta-refresh, or Ajax calls. Using sleep in PHP will pause the script execution for a specified number of seconds, which can be a simple way to introduce a delay in the loop. However, this will block the entire script execution, potentially causing performance issues. On the other hand, using meta-refresh in HTML will reload the page after a specified number of seconds, effectively slowing down the loop. This method allows the rest of the script to continue running while the page refreshes, but it might not be suitable for all scenarios. Lastly, using Ajax calls in PHP can asynchronously fetch data from the server without reloading the entire page, allowing for a more seamless user experience. This method can be more complex to implement but offers greater flexibility and control over the loop execution.

// Using sleep to slow down a loop in PHP
for ($i = 0; $i < 10; $i++) {
    // Do something
    sleep(1); // Pause for 1 second
}