CODEWITHSUNDEEP
phparraysassociative-arrayconventionsternary-operator
Maverick
Maverick

Reputation: 3059

Least verbose way of defining a default array value

Is there a cleaner way to check for array values to prevent PHP notices? Currently I do this: 

$email      = (isset($_POST['user_email']))      ? $_POST['user_email']      : '';
$first_name = (isset($_POST['user_first_name'])) ? $_POST['user_first_name'] : '';
$last_name  = (isset($_POST['user_last_name']))  ? $_POST['user_last_namel'] : '';
$birthday   = (isset($_POST['user_last_name']))  ? $_POST['user_last_namel'] : '';

Is there a way to do something like JavaScript where you just provide a default, like this?

user.email = response.email || '';

I don't want to suppress notices, but these ugly checks clutter up my code. I'm on PHP 5.2.6.

Upvotes: 3

Views: 150

Answers (5)

Ihor Burlachenko
Ihor Burlachenko

Reputation: 4905

You can use DefaultArray from NSPL:

$post = defaultarray('', $_POST);

$email = $post['user_email'];
$first_name = $post['user_first_name'];
$last_name = $post['user_last_name'];
$birthday = $post['user_birthday'];

Upvotes: 0

webbiedave
webbiedave

Reputation: 48897

You can create a function:

$email      = getPost('user_email');
$first_name = getPost('user_first_name');
$last_name  = getPost('user_last_name');
$birthday   = getPost('user_birthday');


function getPost($key, $default = '')
{
    if (isset($_POST[$key])) {
        return $_POST[$key];
    }
    return $default;
}

Putting it in a function also let's you do additional sanitizing more easily, e.g., trim(), if desired.

You can also pass a default value that will be returned:

$flavor = getPost('flavor', 'vanilla'); // if $_POST['flavor'] is not set, 'vanilla' is returned

Upvotes: 5

Tadeck
Tadeck

Reputation: 137320

I have seen at least three ways of doing this.

Adding array with defaults

$options = $_POST + $defaults;

where $options is an associative array having everything $_POST had, but with added keys and values from $defaults (unless there was a value in $_POST for specific key in $defaults, then this specific key/value pair from $defaults is ignored and value for this specific key in $_POST is not replaced).

Merging with array of defaults

As shown by @mario (use array_merge()):

$options = array_merge($defaults, $_POST);

Using helper functions...

...such as Kohana's Arr::get() helper:

/* ... */
public static function get($array, $key, $default = NULL)
{
    return isset($array[$key]) ? $array[$key] : $default;
}
/* ... */

which has some advantage of easily replacing default value (which, by default is NULL). It can be used like that:

echo Arr::get($_POST, 'user_email');

or:

echo Arr::get($_POST, 'user_email', 'N/A');

Upvotes: 2

mario
mario

Reputation: 145482

If you have a set of attributes, then one concise option is array_merge. Note that the defaults go first:

 $post = array_merge(
      array("email" => "", "first_name" => "", "last_name" => "", "birthday" => ""),
      $_POST
 );

Then just access them as is:

 $email = $post["email"];   // it's assured there is some value

An even more compact way to localize a limited set of variables is extract() in combination with array_intersect_key(). But only in that combination - to prevent importing arbitrary variables:

 extract(array_merge($defaults, array_intersect_key(array_filter($_POST), $defaults)));

Upvotes: 3

Eugen Rieck
Eugen Rieck

Reputation: 65274

function assure(&$a, $default=null) {
  if (!isset($a)) $a=$default;
  return $a;
}

$email=assure($_POST['user_email'],'');
$first_name=assure($_POST['user_first_name'],'');

Upvotes: 0

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