loops?

help with loops

[penguinpage]

I need a script that will write....

<!-- begin

if ($q#==$a#) {
$c=($c+1);
$v#="1";
}

end -->

X amount of times where # represents the number of the loop... if X=3 for example it would act like this

<!-- begin

if ($q1==$a1) {
$c=($c+1);
$v1="1";
}
if ($q2==$a2) {
$c=($c+1);
$v2="1";
}
if ($q3==$a3) {
$c=($c+1);
$v3="1";
}

END -->

This would be of great help because the full script is used to validate exercises on a school study site

[DrDoc]

echo "<!-- begin

";

for($i=1; $i<=$x; $i++) {
echo "if (\$q$i==\$a$i) {
\$c=(\$c+1);
\$v$i="1";
}

";
}

echo "end -->
";

[penguinpage]

this needs to be in a php file and use php functions so that doesn't work

[Glacai]

My php is not too good but in c you would need to use an array, php maybe..

for($i=0; $i<$x; $i++) {
if($q[i] == $a[i]) {
$c++;
$v[i] = "1";
}
}

[jamesa]

Sounds like a job for variable variables [php.net]

[jatar_k]

$counter = 0; 
while (isset(${"q" . $counter})) { 
  if (${"q" . $counter}==${"a" . $counter}) { 
  $c=($c+1); 
  $v1="1"; 
 } 
 $counter++; 
} 

the test in the while loop may be wrong but the method is correct.

[DrDoc]

this needs to be in a php file and use php functions so that doesn't work

Ehm, yes... And the code I wrote was meant to be in that PHP script...

<?php
for($i=1; $i<=$x; $i++) {
echo "if (\$q$i==\$a$i) {
\$c=(\$c+1);
\$v$i="1";
}

";
}
?>

If $x is 4 it will print:

if ($q1==$a1) {
$c=($c+1);
$v1="1";
}
if ($q2==$a2) {
$c=($c+1);
$v2="1";
}
if ($q3==$a3) {
$c=($c+1);
$v3="1";
}
if ($q4==$a4) {
$c=($c+1);
$v4="1";
}

So, I don't understand why it doesn't work?

[vincevincevince]

drdoc, i believe what penguinpage means is that the code that he wants returned must be run - he's not outputting code for people to look at - he wants to generate that code to run in php

drdoc's code will work if you buffer the output and write it to a file.php then include("file.php");

;-)

[hakre]

... or you use eval() [php.net] instead. then you won't need to save a file at all or buffer the output:

<?php 
for($i=1; $i<=$x; $i++) { 
[b]eval([/b]"if (\$q$i==\$a$i) { \$c=(\$c+1); \$v$i=\"1\";}"[b])[/b];
}
?>

(just added it to drdocs code and escaped the last two ", because they weren't.

[DrDoc]

That's a really nice solution, hakre. And thanks for spotting the problem with the quotation marks :)

[hakre]

nice solution maybe but, the eval on that place is really - ehm let's say - nuts.

my example is just a overhead for the script. even the php-developers optimized the eval function, it could be done direct instead:

<?php 
for($i=1; $i<=$x; $i++) {
$v_q = '$q'.$i;
$v_a = '$a'.$i;
$v_v = '$v'.$i;
if ($$v_q==$$v_a) { $c++; $$v_v="1"; }
} 
?>

the previously posted code was just to point out, that eval might be used and is powerfull (like variable variables, too).

[penguinpage]

thanks but i've tried all of these snippets of code and each one returns a Parse Error. I've never worked with loops before so this is all really new to me and i cant debug it. here are copies of all the files used... 
<!-- begin a sample form that points to check.php 
<form name="ex" method="post" action="../check.php"> 
<input type=hidden name=fldr value=formal> 
<input type=hidden name=ex value=ex1> 
<p>Du, ihr, oder Sie?: which word would be used to properly address each of the following?</p> 
<br> 
1)Your mom:<br> 
<input type="radio" name="q1" value="Du">Du<br> 
<input type="radio" name="q1" value="Ihr">Ihr<br> 
<input type="radio" name="q1" value="Sie">Sie<br> 
<br> 
2)The school's German teacher:<br> 
<input type="radio" name="q2" value="Du">Du<br> 
<input type="radio" name="q2" value="Ihr">Ihr<br> 
<input type="radio" name="q2" value="Sie">Sie<br> 
<br> 
3)Rufus the fat llama:<br> 
<input type="radio" name="q3" value="Du">Du<br> 
<input type="radio" name="q3" value="Ihr">Ihr<br> 
<input type="radio" name="q3" value="Sie">Sie<br> 
<input type=submit value="Check my answers already!"><input type=reset value="I messed up...reset it"> 
--> 
<!-- begin answer file called by include("$fldr/$ex.php"); 
<? 
$x=3 
// x is the number of questions 
$tut="Formal/Familiar: exercise 1"; 
// just a name 
$a1="Du"; 
// question 1's answer 
$a2="Sie"; 
// question 2's answer 
$a3="Du"; 
// question 3's answer 
?> 
--> 
<!-- begin file: check.php 
<? 
if ($fldr==""){ 
echo "<body onload=\"(window.location='index.htm')\">"; 
} 
$c=0; 
include("$fldr/$ex.php"); 
////////////////////////////////////////////////////////// 
// 
// THIS IS WHERE THE CODE I'M LOOKING FOR GOES 
// 
///////////////////////////////////////////////////////// 
?> 
<html><head><title><? echo $tut;?></title></head> 
<body bgcolor=black text="d0d0d0"> 
<center><h1>Results</h1><br><h2><? echo $tut;?></h2><hr width=80%> 
You scored <b><font color="00cccc"><? echo $c;?> out of&nbsp;&nbsp;7</font></b>.</center><hr width=80%> 
<? 
/////////////////////////////////////////////////////////// 
// 
// A MODIFIED VERSION OF THE CODE WOULD GO HERE 
// IT WOULD ECHO THE RESULTS OF EVERY QUESTION  
// EX: echo "you got question 1 right/wrong"  
// I can write this part of the code...  
// After i see how the other code was written  
// 
////////////////////////////////////////////////////////// 
?> 
--> 
the form would be in 
/formal/ex1.htm 
the php answer file  
/formal/ex1.php 
the check.php file 
/check.php 
I know this is a huge problem but I know very little about php