php echo the result while iterating through the loop

问题

I am execution loop and inside loop there is data processing function inside loop.

  for($i = 0 ; $i <=680 ; $i = $i + 40)
    {
          $url = 'http://www.yelp.com/biz/franchino-san-francisco?start=80';
          $root = yelp($url);
          var_dump($root);
    }

This loop takes long time to execute, and results are echoed at the end when entire loop completes.

How can I echo the result during each iteration?

Actually what happens here? does to result are stored in buffer and at the end echoed or what?

回答1:

PHP buffers the output.

If you want to output stuff to the browser immediately you can use the flush() and ob_flush() functions:

for ($i = 0; $i <= 680; $i += 40) {
    $url = 'http://www.yelp.com/biz/franchino-san-francisco?start=80';
    $root = yelp($url);
    var_dump($root);
    flush();
    ob_flush();
}

回答2:

If you are executing PHP through a web-page, this would be the behaviour.

PHP is a server side language and all code will be executed before displaying the output to the client. (using a browser)

If you want to display the result within the loop, better use console / cmd (command line)

Here is something that will help you use PHP with commandline.

来源：https://stackoverflow.com/questions/23355484/php-echo-the-result-while-iterating-through-the-loop