What's the use of ob_start() in php?

php output-buffering
Aditya Shukla picture Aditya Shukla · Dec 9, 2010 · Viewed 301.5k times · Source

Is ob_start() used for output buffering so that the headers are buffered and not sent to the browser? Am I making sense here? If not then why should we use ob_start()?

Answer

Riley Dutton picture Riley Dutton · Dec 9, 2010

Think of ob_start() as saying "Start remembering everything that would normally be outputted, but don't quite do anything with it yet."

For example:

ob_start();
echo("Hello there!"); //would normally get printed to the screen/output to browser
$output = ob_get_contents();
ob_end_clean();

There are two other functions you typically pair it with: ob_get_contents(), which basically gives you whatever has been "saved" to the buffer since it was turned on with ob_start(), and then ob_end_clean() or ob_flush(), which either stops saving things and discards whatever was saved, or stops saving and outputs it all at once, respectively.

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