Re: Trying to understand what is happening in this code

Stuart, Jose - Thanks for your quick response. Are you saying that the processor echos all the html tags it sees. Is it doing something like this to the script: echo <body> echo <h1>The first twenty Fibonacci numbers:</h1> echo <ul> <?php $first = 0; $second = 1; for ($i = 0; $i < 20; $i++) { ?> echo <li><?php echo $first + $second ?></li> <?php $temp = $first + $second; $first = $second; $second = $temp; } ?> echo </ul> echo </body> Or is it just the line in question that is being echoed? ----------------------------- Nathan Grey 404-337-9005 On Fri, Oct 11, 2013 at 11:06 AM, Stuart Dallas <stuart@3ft9.com> wrote: > On 11 Oct 2013, at 16:01, Nathan Grey <greynng@gmail.com> wrote: > > > Hi - I am new to PHP so this is probably a very rudimentary question. I > > posed it over at Stack Overflow and got several responses but none of > them > > clarified the issue for me. > > > > > > http://stackoverflow.com/questions/19309369/trying-to-understand-how-these-php-sections-work-together > > > > Here's the code I am trying to understand: > > > > <body> > > <h1>The first twenty Fibonacci numbers:</h1> > > <ul> > > <?php > > $first = 0; > > $second = 1; > > for ($i = 0; $i < 20; $i++) { > > ?> > > <li><?php echo $first + $second ?></li> > > <?php > > $temp = $first + $second; > > $first = $second; > > $second = $temp; > > > > } ?> > > </ul></body> > > > > This code produces an unordered list of the first 20 Fibonacci numbers. I > > understand that HTML and PHP can be interspersed. I also understand that > > the PHP processor will look over the code and pick up the code that is > > between the opening and closing PHP tags. Here's where I am confused: > > > > 1. Can the processor really reassemble a for-loop that is broken into > > segments by opening and closing tags? It seems like the integrity of the > > loop would be broken. I would expect that the entire loop would have to > be > > contained within a single pair of opening and closing tags for it to > work. > > > > 2. Even if the processor is able to reassemble the loop seamlessly, how > do > > the <li> tags get included in the loop since they fall outside of the PHP > > tags? > > Probably the easiest way to understand what's happening is to assume that > PHP converts anything in the file that's outside PHP tags in to echo > statements, and then executes the result. This isn't too far from what > actually happens. > > PHP compiles any script in to bytecodes, which it then executes. Anything > outside PHP tags does, essentially, get passed in to the echo language > construct. > > Does that help at all? > > -Stuart > > -- > Stuart Dallas > 3ft9 Ltd > http://3ft9.com/ >