如何在一个字符串中转换更多数组？ （数组到字符串）

How an inside function preg_replace_callback_array transform array to string?

Array
(
    [0] => string
)
Array
(
    [0] => string
)
Array
(
    [0] => string
)

string(6) "string"
string(6) "string"
string(6) "string"

I want to have:

string(18) "stringstringstring"

How to do it?

Looks like there's a PHP function called implode that should do the trick: http://php.net/manual/en/function.implode.php

<?php

$data = [
    ["string"],
    ["string"],
    ["string"]
 ];

$strs = [];

array_map(function($x) use (&$strs) {
    foreach($x as $v) $strs[] = $v;
}, $data);

var_dump($strs);