php - How to pair items in array -

how pair items in array

$array= array(1,2,3,4,5,6,7,8,9);

i display array as

12

23

34

45

56

67

78

89

how can achieve this?

this code looking for:

$array= array(1,2,3,4,5,6,7,8,9);  for($i=0;$i<count($array);$i++){     if (isset($array[$i+1])) // mentioned in comments, avoid "php notice:  undefined offset: 9"         echo $array[$i].$array[$i+1] .'<br>'; }