Put all indexs of array in a comma separated string [closed]

Question

I have an array that looks like this:

array('first' => 'value1', 'second' => 'value2', ...);

How can I get all the keys and put them in a comma separated string?

At the very end I need something like this, to do a query:

values IN ('first','second',...)

Thanks

Tapioca

array_keys() would do that for you. – Octopus

@Jack not quite. That will give them an array of the keys. They will then have to implode() that. – Feldstein

Have a look at this question. It deals with a similar problem. – Cuevas

@PatrickJamesMcDougle op already has implode tag on the question, so my comment should give enough information. – Octopus

BTW, instead of injecting that string directly, you really should make sure that you are using PDO prepared statements for this. php.net/manual/en/pdo.prepared-statements.php – Feldstein

Answer 1

should be enough:

echo "'".implode("','", array_keys($array))."'";

Canter

Comment deleted because I was being dumb. – Feldstein

nope, explode = string to array; implode = array to string – Canter

@PatrickJamesMcDougle hapens to the best of us :D – Canter

Answer 2

array_keys will grab all the keys, implode will combine them into a string.

implode("','", array_keys($array));

Clincher

Answer 3

The simple answer is to use array_keys() to get the array indices.

However, since you're using this in SQL, it's important to also properly escape the values:

$db = new PDO( ... );
$sql .= "value IN (" . 
        join(', ', array_map(array($db, 'quote'), array_keys($arr))) . ")";

Or, when you prefer using prepared statements:

$stmt = $db->prepare('... WHERE value IN (' . 
    join(',', array_fill(0, count($arr), '?')) . ')');
$stmt->execute(array_keys($arr));

Colloidal

IMHO it would be much better to use VALUE IN (?) and ->execute(array(implode("','",array_keys($array)) – Canter

@Canter I wouldn't say much better, but that's a good alternative :) – Octopus

Answer 4

$result = '';
$keys = array_keys($array);

foreach($keys as $key) { 
$result .= $key.',';
}

$result = rtrim($result, ',');

Been

this will lead to first, second not to 'first','second' – Canter

Answer 5

Have a at array_keys. It seems like the thing you need. To combine the keys, use implode as suggested by many other users:

implode("','", array_keys($array));

Welfarism