Answer by Unicco for Fastest way to implode an associative array with keys

Use array_walk for this.

$arr = ["key"  => "value","key2" => "value2",];array_walk($arr, function(&$value, $key) {    $value = "{$key}: {$value}";});implode("<br/>", $arr)

Result

key: value<br/>key2: value2<br/>