How to access a $_POST item through the following array kind of syntax?

If i send four POST variables, but the second one — I dont know that th开发者_StackOverflow社区e name="" tag will be; how can I access it? Can i use $_POST[1] or not?

Here's one solution using internal pointers:

if(count($_POST) > 1){ // just a check here.
  reset($_POST); // reset the pointer regardless of its position
  $second_value = next($_POST); // get the next value, aka 2nd element.
}

By the way with regards to the numeric index: PHP $_POST and $_GET are associative arrays! They do not support something like $_POST[0] or $_POST[1]. They will return NULL because they are not set. Instead $_POST["name"] would work.

From the PHP Manual: "An associative array of variables passed to the current script via the HTTP POST (or GET) method."

i have a handy function for this

function nth($ary, $n) {
     $b = array_slice($ary, intval($n), 1); 
     return count($b) ? reset($b) : null;
}

in your case

$foo = nth($_POST, 1);

foreach( $_POST as $key => $value ){
    if( is_int($key) ) //do something with $value
}

This will work if you know the other $_POST values have names in your forms (i.e., keys that aren't numbers).

You can loop through it:

foreach ($_POST as $k => $v) {
  if (substr($k, 0, 3) == 'id_') { 
    // do stuff
  }
}

But it really depends on what the criteria for the search is. In the above example it's pulling all the POST variables that start with "id_". You may be able to do it simpler if you have a different/better criteria.

You can if you convert it using array_values() first.

Example

<?php

$a = array(
        "first key" => "first value",
        "second key" => "second value",
);

$v = array_values($a);
echo "First value: {$v[0]}\n";

?>

Output

$ php -f a.php
First value: first value

EDIT: Thanks for commentators pointing out the initial error.

use

<?php
print_r($_POST);
?>

this will give you an idea of what is the key of the field you don't know.

Make a copy :

$vars = $_POST;

Remove the names you know :

unset( $vars[ "known variable 1" ] );
unset( $vars[ "known variable 2" ] );

All that remains is the variables you need : extract them with array_values or enumerate them with foreach, whatever.

a simple for each will do the trick if you do not know the array keys on the $_POST array

foreach($_POST as $key=>$value):
   print 'key'.$key.' value'.$value
endforeach; 

But it is recommended to know what your post variables are if you are planning on processing them.