Young thanks for the explanation.
However the code below (without ob_start()) also produce the same effect i.e. it displays all the numbers together at the end of the script like this 1,2,3,4,5,
echo $i. ",";
If we are NOT using ob_start(), it should display the numbers one at a time like this:
Sorry but I am still confused with this particular example. I mean why the script is still holding the output even when we are NOT using ob_start()?
1,2,3,4,5, [final output]