PHP如何检查数组是否没有键和值

Question

I am using one custom CMS developed by someone and getting issue to check the array result.

The function returns an array of username by passing userids array.

Example Code

$all_users = "1,5,9,10,25,40"; // getting from database

$user_ids = explode(',', $all_users);
$usernames  = get_userids_to_usernames($user_ids); //this returns usernames array by passing uesrids array

If the database has not users in the column than the function is returning weird empty / null array as below.

var_dump($usernames);

array(1) { [""]=> NULL }

print_r($usernames);

(
    [] => 
)

Now issue is, I want to check if array is empty or has value in return but I have tried everything is_null , empty , count($usernames) > 0 but none of these working.

Can anyone please help me to check conditionally if array has value or empty like above empty result.

Answer 1

Here is a workaround

if (array_key_exists('', $a) && $a[''] === null) {
    unset($a['']);
}

then check on emptiness

Answer 2

You can use in_array to check if the array has an empty value and array_key_exists to check the key.

in_array("", $array)
array_key_exists("", $array)

http://php.net/manual/en/function.in-array.php

http://php.net/manual/fr/function.array-key-exists.php

Answer 3

Iterate through array, and check if keys or values are empty or null

$newarray = [];
foreach($array as $key=>$value)
{
    if(is_null($value) || trim($value) == '' || is_null($value) || trim($key) == ''){
    continue; //skip the item
  }
        $newarray[$key] = $value;
}

Answer 4

If you want to use empty with it, try array filter

if (empty(array_filter($arr))) {
    //Do something
}

Array filter will automatically remove falsey values for you, and you can include a callback should you need more flexability.