Value From Array At Index (PHP)

Question

How would I get a value from two arrays at a specific index? I have a $usernames array, and a $passwords array. I also have variables called $username and $password (which are the username and password user entered).

I want to get the index of $username in $usernames and compare it to the index of $password in $passwords. If they match, username and password are correct. If not, they are not correct.

I know array's are probably not the best way to do it, but its only for like 5 people and does not really have to be top secret, just a simple password protect.

I have tried:

<?php
$usernames = array("test1", "test2");
$passwords = array("password1", "password2");
$list = array($usernames, $passwords);
if (in_array($userName, $usernames)) {
   $userNameIndex = returnIndex($usernames, $userName);   
   $passWordIndex = returnIndex($passwords, $password);   
   echo("it says:<br />");
   echo($userNameIndex . " and password: " . $passWordIndex);
} else {
  echo("Not In Array");
}
?>

<?php
function returnIndex($array, $value) {
    $ar = $array;

    $searchValue = $value;

    for($i=0; $i< count($ar); $i++) {
        if($ar[i] == $searchValue) return i;
    }
}
?>

However it returns

it says:

and password: i

Save yourself a lot of work and use an associative array instead: $users = array("user1" => "password1", "user2" => "password2"); then check with just if ($users[$username] == $password) { .... — Philipp Reichart
– Philipp Reichart, Commented Mar 24, 2012 at 18:11
Tip: In if($ar[i] == $searchValue) return i; replace i with $i to make it valid PHP code. Watch your errors, enable warnings. — hakre
– hakre, Commented Mar 24, 2012 at 18:11

Jon · Accepted Answer · 2012-03-24 18:03:50Z

First of all, you don't need a function returnIndex because PHP already has one: it's called array_search.

You would use it like this:

$usernames = array("test1", "test2");
$passwords = array("password1", "password2");

$userIndex = array_search($username, $usernames, true);
$passIndex = array_search($password, $passwords, true);

if ($userIndex !== $passIndex || $userIndex === false) {
    die("authentication error");
}

However: having separate arrays of usernames and passwords, while it does work, is not really the most straightforward approach. It would be better if you have each username and its password "close together". If the decision is entirely in your hands you could for example use usernames as keys and passwords as values in the same array:

$auth = array("test1" => "password1", "test2" => "password2");

This way you can do it much more easily and without any need for business functions:

if (!isset($auth[$username]) || $auth[$username] !== $password) {
    die("authentication error");
}

Rafe Kettler · Accepted Answer · 2012-03-24 17:57:44Z

2

Do you mean return $i in your search function? Also, $ar[$i]?

Though, honestly, it'd be smarter to use the standard library function for this, array_search(), which returns the index of an element of an array if it's in the array.

answered Mar 24, 2012 at 17:57

Rafe Kettler

77.1k21 gold badges160 silver badges151 bronze badges

2 Comments

Ali Hamze Over a year ago

I have actually been through php.net/array and it does not mention array_search() until the bottom comments section and it does not explain what it is doing.

Rafe Kettler Over a year ago

@Ali try the function reference for arrays. The particular page for array_search() is at php.net/manual/en/function.array-search.php.

Kishor Kundan · Accepted Answer · 2012-03-24 18:13:18Z

0

If i had to prefer something apart from array_search, I would use foreach rather than for

foreach($array_name as $key => $value) {
    echo $key;     // echoes index of an array
    echo $value;   // echoes value of an array
}

answered Mar 24, 2012 at 18:13

Kishor Kundan

3,1651 gold badge25 silver badges30 bronze badges

Comments

Stefan · Accepted Answer · 2012-03-24 17:58:19Z

-2

Use array_search() instead?

http://www.w3schools.com/php/func_array_search.asp

UPDATE:

$userNameIndex = array_search($userName, $usernames);
$paswordIndex = array_search($pasword, $passwords);

answered Mar 24, 2012 at 17:58

Stefan

3,8993 gold badges28 silver badges39 bronze badges

4 Comments

user895378 Over a year ago

Please don't reference w3fools.com as a Stack Overflow answer. At least point to the relevant PHP manual entry.

Stefan Over a year ago

@rdlowrey: Why not? Why is w3schools not an acceptable reference?

user895378 Over a year ago

@Stefan Just follow the link in my comment to learn more. If you'd like, I can add a downvote then you can delete your answer to get the "Peer Pressure" badge :)

Stefan Over a year ago

Monkey-mind learned-association train: 'References w3schools - don't have to think - just VOTE DOWN - and feel important.' Who cares if reference was accurate or suitable enough in this case or not. Let's not waste our important time on that, shall we. (Sarcasm intended). Ever heard of the term "throwing the baby out with the dishwater?"

Collectives™ on Stack Overflow

Value From Array At Index (PHP)

4 Answers 4

Comments

2 Comments

Comments

4 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

Comments

2 Comments

Comments

4 Comments

Your Answer

Sign up or log in

Post as a guest

Related