Variables and for loops

[kcdjax]

I have a bunch of variables, and the number varies depending on the dates the user selects (i.e. date1, date2, date3, ...). I also have a variable 'sets' that tells me how many dates they have choosen. I'm using a for loop to add the info to a database. Why isn't $date1 the same as $date$i if $i=1? Any suggestions on how I should do this?

for($i=1; $i<=$sets; $i++){
$query = "insert into ride values ('$userid','$date$i,'$distance$i','$duration$i','$avespeed$i')";
$result = mysql_query($query);
}

[herve]

I'm not sure to get it all, but you
could use an array instead and the count()
function to get the nb of items in the array

$nb = count ($date_array);

for ($k=0;$k<$nb;$k++)
{
$mydate = $date_array[$k]

$query = "INSERT INTO ...
       VALUES ... ,'$mydate',

}

[smarlowe]

What you are trying to do is called variable variables. It works like this:

$a = "abc";
$abc = "this is the string to print";
print $$a;

What's happening is that the string "abc" assigned to $a in the first line is used in the third line to create a variable variable.

Now, the way you were trying to do it was:use $date$i which is close. But you need a few things. You need two $ signs at the front, and it's a good idea to use a pair of {} brackets to tell the interpreter exactly what part of $date$i is the variable you want to use as a variable variable.

so:

print ${$date.$i};

will tell php to concatenate $date and $i, then the ${} construct says to use that as a variable name.

It would likely be better if you could just feed an array into your program. You can do this by building a form with elements named like this:
(Note, &lt; replaced with [ since phorum has some issues with angle brackets)

[input type=text name=field[0]]
[input type=text name=date[0]]

or, conversly, you can leave the key empty:

[input type=text name=field[]]

Or you can use a hash type index for your array:

[input type=text name=[field[bubba]]

etc...

These types of vars are much easier to parse. Say you used the field[] naming convention. you could find how many elements were in the field array by using count:

print count($field);

and you could see all your array keys with this simple little hack:

print implode(":",array_keys($field));

good luck, hope that helps.