PHP array delete by value (not key)

Question

I have a PHP array as follows:

$messages = [312, 401, 1599, 3, ...];

I want to delete the element containing the value $del_val

Answer 1

If you know for definite that your array will contain only one element with that value, you can do

$key = array_search($del_val, $array);
if (false !== $key) {
    unset($array[$key]);
}

If, however, your value might occur more than once in your array, you could do this

$array = array_filter($array, function($e) use ($del_val) {
    return ($e !== $del_val);
});

Note: The second option only works for PHP5.3+ with Closures

Answer 2

To delete multiple values try this one:

while (($key = array_search($del_val, $messages)) !== false) 
{
    unset($messages[$key]);
}

Answer 3

As per your requirement "each value can only be there for once" if you are just interested in keeping unique values in your array, then the array_unique() might be what you are looking for.

Input:

$input = array(4, "4", "3", 4, 3, "3");
$result = array_unique($input);
var_dump($result);

Result:

array(2) {
  [0] => int(4)
  [2] => string(1) "3"
}

Answer 4

function array_remove_by_value($array, $value)
{
    return array_values(array_diff($array, array($value)));
}

$array = array(312, 401, 1599, 3);

$newarray = array_remove_by_value($array, 401);

print_r($newarray);

Output

Array ( [0] => 312 [1] => 1599 [2] => 3 )

Answer 5

$fields = array_flip($fields);
unset($fields['myvalue']);
$fields = array_flip($fields);

Answer 6

here is one simple but understandable solution:

$messagesFiltered = [];
foreach ($messages as $message) {
    if (401 != $message) {
        $messagesFiltered[] = $message;
    }
}
$messages = $messagesFiltered;