How to convert multiple array to single array [duplicate] - php

Question

This question already has answers here:
Convert array of single-element arrays to a one-dimensional array
(8 answers)
Closed 3 years ago.
Sorry for asking this silly question here. I am very new to PHP language.
I am trying to know how can i convert the array.
I want to convert this array to single array like.
Convert this :-
Array ( [0] => user )
Array ( [0] => user1 )
Array ( [0] => user2 )
Array ( [0] => user3 )
Array ( [0] => user8 )
Array ( [0] => user7 )
Array ( [0] => user6 )
Convert To :-
Array("user", "user1", "user2", "user3", "user4", "user5", "user6");

Answer 1

To "Merge" multiple arrays into one, you can use array_merge()
A good example would be:
$array_1 = array('user');
$array_2 = array('user1');
$array_3 = array('user2');
$combined_array = array_merge($array1,$array_2,$array_3);
var_dump($combined_array);

Answer 2

Something like this should do:
while($row = $result->fetch_array(MYSQLI_NUM)) {
$users[] = $row[0];
}

Answer 3

Pack or collect all arrays into a parent array.
Then you only need to pass an array as a parameter when calling array_merge.
Update: it is better to use array_column.
$arr = [];
$arr[] = array('user');
$arr[] = array('user1');
$arr[] = array('user2');
$one_dim_array = array_merge(...$arr);
//or better
$one_dim_array = array_column($arr,0);
echo "<pre>".var_export($one_dim_array, true);
Result:
array (
0 => 'user',
1 => 'user1',
2 => 'user2',
)
Try it yourself : Sandbox

Answer 4

Another alternative, aside from array_merge, for the case of an arbitrary number of subarrays, you could use array_reduce and build your final array:
$inArray = [['user'],['user1'],['user2'],['user3'],['user8'],['user7'],['user6']];
$inArray = array_reduce($inArray, function($arr, $elem){
$arr[] = $elem[0];
return $arr;
});
Of course, the straightforward solution would be to use array_merge:
$inArray = array_merge(...$inArray);