Using a loop to add variables from a form into an array

Kenw

What I'm trying to do is use a for loop to multiple similarly named variables from a form into an array. Here is the relevant line of code I have that is not working:

$varName[ $counter ] = $_REQUEST[ 'varName' [$counter] ];

Obviously the part that is not working is the information inside the $REQUEST call (should I be using $POST or $GET instead of $REQUEST?). Is what I'm trying to do even possible or will I need to simply assign each var one by one?

Thanks in advance for the help. Any suggestions on a better way to do this would be more than welcome.

subwayman

Use $POST or $GET which already has your data set up in an associated array.

nickadeemus2002

What I'm trying to do is use a for loop to multiple similarly named variables from a form into an array. Here is the relevant line of code I have that is not working:

$varName[ $counter ] = $_REQUEST[ 'varName' [$counter] ];

well, i can see why this code can't loop through an array. as stated above, php already puts your form variables into an array for you, so you shouldn't have to do it. but, if you wanted to loop through an array, you could use:

for ( $i = 0; $i <= $number_of_form_vars; $i++)
echo "$varName[$i];

but i don't think looping through the array is really the issue here. since the goal is to loop through an array so you do not have to declare them one at a time somewhere else in the code, i think the questions to ask would be:

how does php assign keys for form arrays? with numerical or non-numerical indexes? if non-numerical, does php use the 'name' attribute in the form to handle the form data? i really am not sure how it works. but, once it's understood how php assigns indexes to form array elements, it would be interesting to see if someone can declare them on an 'action' page with a loop.

subwayman

PHP can do both. If you use the form array[21] then php will keep that index for you. You can also use a key->value form which allows you to assign a key to each element, e.g. array['addressline1']. Note though that in reality there is no real difference, simply that the key can be either an integer or a string. So you can use $names[21] and $names['mother'] in the same array. If you try to assign a value to an array without specifying a key then it will assume intger and take the highest integer key to date and add one to get the new key. There is one other useful function: unset($array[key]) which effectively removes the element from the array (not just make the value null).

nickadeemus2002

PHP can do both.

true. but what i was hinting at was to find out exactly how php stores the index value of an array that holds data from a form. so, like the original poster stated, how does one loop through the 'auto assigned' array from a form? does php auto assign numerical index values?

let's say i have the following variables on an action page:

<? php
//associate form variables for action script to handle product
$tireqty = $_POST['tireqty'];
$oilqty = $_POST['oilqty'];
$batteryqty = $_POST['batteryqty'];
....
..
.
?>

obviously, the $_POST['X'] variables come from a user-entry form, which used the 'post' method. php automatically holds these variables in an array so they can be accessed from another page. the issue boils down to finding out how a developer can access those elements without having to list all X items individually. i've run into the same problem as the op; it takes forever to code large form lists on another page. it would be more efficient to use an array loop to access these elements. however, i have no idea what index values php assigns to tireqty, oilqty, batteryqty, and so on in this auto-generated array. if i could figure out the index values, i would also love to loop through them instead of having to list them one by one. any suggestions?

subwayman

I don't think you can do what you want the way you want to do it. An associated array does not have correspondong integer key values. What you can do is use something like:

foreach ($_POST as $key => $value) {
   echo "Key: $key; Value: $value<br />\n";
}

So within each iteration of the loop you will get a key and value 'for each' element of the array. The above code will effectively print out the array giving both the key and value. For a POST form it will therefore print out the input form field name and the value posted. I think this will give you want you want.

Kenw

Thank you both for the feedback. Guess I can't really do what I was trying to but I should be able to make your code produce the desired end result subwayman.