How to search $_POST for dynamic added input values? - php

Question

I have a form where i add inputs on the fly.
The names of the inputs start the same but has a number added on the end:
<input type="number" name="number_of_floors_house_'+i+'">
Now, when i post my form i would like to loop threw this inputs.
So i need something like array_search($_POST['number_of_floors_house_%']
Or find all $POST['keys'] that starts with 'number_of_floors_house' and loop them threw to get it's values :)
Can you help please?
EDIT
I've tried:
$houses_and_floors = array_search('number_of_floors_house_%', $_POST);
var_dump($houses_and_floors);

Answer 1

Change your input to something like this:
<input type="number" name="number_of_floors['+i+']">
The square brackets make the input submit as an array, so you could then loop through all the values easier:
foreach($_POST['number_of_floors'] as $house_number => $value) {
// $house_number will be whatever number was added to the form element.
// $value is the actual input boxes value
}

Answer 2

You could use an array_filter() to pick out the pieces of $_POST you actually want like this
//fake up a post array
$_POST = ['aa'=>1, 'bb'=>2, 'number_of_floors_house_1'=>2, 'number_of_floors_house_2'=>2,'number_of_floors_house_3'=>4];
function picker($v, $k)
{
return strpos($k, 'number_of_floors_house') !== FALSE;
}
$res = array_filter($_POST, 'picker', ARRAY_FILTER_USE_BOTH);
print_r($res);
RESULT
Array
(
[number_of_floors_house_1] => 2
[number_of_floors_house_2] => 2
[number_of_floors_house_3] => 4
)

Answer 3

You can filter for array keys matching a given prefix with array_filter() and strncmp():
$prefix = 'number_of_floors_';
$length = strlen($prefix);
$nof = array_filter($_POST, function($key) use ($prefix, $length) {
return strncmp($prefix, $key, $length) === 0;
}, ARRAY_FILTER_USE_KEY);
This will filter your post data for all array members with the defined prefix. Note that we're checking the prefix length outside the function to avoid a redundant repeated evaluation inside the function (which is executed for once each array member). You could, of course, also just hard-code this for a single use-case and skip the leading variables above:
$nof = array_filter($_POST, function($key) {
return strncmp('number_of_floors_', $key, 17) === 0;
}, ARRAY_FILTER_USE_KEY);
...which would compare the first 17 characters of each key with the defined string. Again, you could also do this with substr() in place of strncmp(), with return substr($key, 0, $length) === $prefix as the filter condition. I chose the former for this example, since it's a function explicitly for the "binary safe string comparison of the first n characters".