RE: [PHP] Re: Found a bug in 4.2.3 re: <TD> and echo vs. <?php?> [solved]

OOOOHHHHHH! Now that makes perfect sense. Thank you Rasmus for that indepth reply and also the , vs . "trick" > -----Original Message----- > From: Rasmus Lerdorf [mailto:rasmus@lerdorf.com] > Sent: Friday, April 04, 2003 10:11 PM > To: Daevid Vincent > Cc: php-general@lists.php.net > Subject: RE: [PHP] Re: Found a bug in 4.2.3 re: <TD> and echo > vs. <?php?> > > > You are getting completely mixed up. Simplifying your example: > > function foo() { echo "foo"; } > > $a = "<TD>".foo()."</TD>"; > > Will you agree that this is bogus code? foo() is not going to return > anything, so the resulting value of $a is going to be "<TD></TD>". > Correct? But while that assignment is happening the foo() > function echoes > something, so you will see "foo" in the output, but it has > nothing to do > with what ends up in $a. Nothing changes when you change the > code to be: > > function foo() { echo "foo"; } > > echo "<TD>".foo()."</TD>"; > > The parser is going to build a string to be echoed since you used the > string concatenation operator (dot). While building that > string one of > the components happen to output something, so that something will get > output. Then the string that was built will be output. So > what you see > is: > > foo<TD></TD> > > Perhaps it is clearer if we make the function return something: > > function foo() { echo "foo"; return "bar"; } > > echo "<TD>".foo()."</TD>"; > > What do you think the output will be here? We build a string > out of the > components, but while building, foo() happens to echo "foo", then we > finish constructing the string and output the final string. > So the result > is: > > foo<TD>bar</TD> > > As someone else pointed out, if you use commas here, things > change a bit: > > function foo() { echo "foo"; } > > echo "<TD>",foo(),"</TD>"; > > The comma syntax for echo is basically a shortcut for executing echo > multiple times. The above is equivalent to writing: > > echo "<TD>"; > echo foo(); > echo "</TD>"; > > In this case things will be output in the correct order as we are no > concatenating a bunch of parts to make a single string before > echoing it > in this case. > > -Rasmus > > On Fri, 4 Apr 2003, Daevid Vincent wrote: > > > Mmm. I'm still not following and not completely convinced. > > > > Changing "echo alarmLightYMD();" to simply > "alarmLightYMD();" in the bottom > > function doesn't print anything in the table cell at all > (for the first test > > case). > > > > While your idea at first makes sense and does seem like a > newbie mistake > > (and you are correct, I do have nested "echo" statements > come to think of > > it). What I don't get is why it's not consistent. > "Expanding" the relevant > > lines, it should be like this: > > > > echo "<TD>".(echo "<IMG > > SRC='images/light_red.gif'>")."</TD>"; > > > > Which fails, and the other line would be (which works): > > > > <TD><?php echo (echo "<IMG > > SRC='images/light_red.gif'>"); ?></TD> > > > > In my book, they're both double echoing the output if you > will... Are you > > with me on that? > > > > So again, why does the second one work and the first one doesn't? > > > > > -----Original Message----- > > > From: Philip Hallstrom [mailto:philip@adhesivemedia.com] > > > Sent: Friday, April 04, 2003 5:20 PM > > > To: Daevid Vincent > > > Cc: php-general@lists.php.net > > > Subject: [PHP] Re: Found a bug in 4.2.3 re: <TD> and echo > vs. <?php?> > > > > > > > > > It's a coding error... at least I think so. > > > > > > change alarmLightMySQL just return the results not "echo" > > > them... echoing > > > them doesn't make much sense inside another echo statement... > > > > > > On Fri, 4 Apr 2003, Daevid Vincent wrote: > > > > > > > Here, try this bullshit... > > > > > > > > I can't upgrade to a more recent version as I'm not in > > > control of the > > > > server, but I've tried it with both 4.1.2 and 4.2.3 on > > > linux with a RH > > > > install. Can anyone confirm or dispute this bug exists in > > > later versions? > > > > > > > > How does a parsing error like this go un-noticed for so long? > > > > > > > > Obviously I took out all the interesting stuff in the page > > > and so that can't > > > > be blamed. This is about as bare skeleton test case as > you can get. > > > > > > > > *sigh* > > > > > > > > ------------snip---------------- > > > > > > > > <?php > > > > function alarmLightYMD() > > > > { > > > > return "<IMG SRC='images/light_red.gif'>"; > > > > } > > > > > > > > function alarmLightMySQL() > > > > { > > > > echo alarmLightYMD(); > > > > } > > > > ?> > > > > <html> > > > > <head> > > > > <title>FUCKED UP PHP Bug #1234170238741023</title> > > > > </head> > > > > > > > > <body> > > > > PHP Version 4.1.2<BR> > > > > PHP Version 4.2.3<BR> > > > > <BR> > > > > Why the FUCK doesn't this work!!!! > > > > <P> > > > > <TABLE BORDER="1"> > > > > <?php > > > > for ($i = 0; $i < 10; $i++ ) { > > > > echo "<TR>"; > > > > echo "<TD>".alarmLightMySQL()."</TD>"; > > > > echo "<TD>this fails!</TD>"; > > > > echo "</TR>"; > > > > } > > > > ?> > > > > </TABLE> > > > > > > > > <HR> > > > > > > > > YET THIS DOES! > > > > <P> > > > > <TABLE BORDER="1"> > > > > <?php for ($i = 0; $i < 10; $i++ ) { ?> > > > > <TR> > > > > <TD><?php echo alarmLightMySQL(); ?></TD> > > > > <TD>this works</TD> > > > > </TR> > > > > <?php } ?> > > > > </TABLE> > > > > </body> > > > > </html> > > > > > > > > ------------snip---------------- > > > > > > > > > > > > > > > > "Ezekiel 25:17. The path of the righteous man is beset on > > > all sides by the > > > > inequities of the selfish and the tyranny of evil men. > > > Blessed is he who in > > > > the name of charity and goodwill shepherds the weak through > > > the valley of > > > > darkness, for he is TRULY his brother's keeper and the > > > finder of lost > > > > children. And I will strike down upon thee with GREAT > vengeance and > > > > FU-U-U-URIOUS anger, those who attempt to poison, and > > > destroy my brothers! > > > > And you will KNOW my name is the Lord, when I lay my > > > vengeance upon thee!" > > > > > > > > > > > > -- > > > > PHP General Mailing List (http://www.php.net/) > > > > To unsubscribe, visit: http://www.php.net/unsub.phpî깚 > > > > ìKev ÍeÚ‡µ > > > > > > > > > > > > > > -- > > > PHP General Mailing List (http://www.php.net/) > > > To unsubscribe, visit: http://www.php.net/unsub.php > > > > > > > > > -- > > PHP General Mailing List (http://www.php.net/) > > To unsubscribe, visit: http://www.php.net/unsub.php > > > > >