unset array Json_encode data format

I have a very interesting question today.

$arr = Array (Array (1,23), Array (1,23), Array (1,23)), Var_dump ($arr);p Rint_r (Json_encode ($arr)); Echo ' <br/> '; foreach ($arr as $k = + $v) {if ($k = = 1) {unset ($arr [$k]);}} Var_dump ($arr);p Rint_r (Json_encode ($arr));d ie;

The result of this code execution is

Can see unset after the Json_encode data format has been changed, studied, probably because the array is removed from the middle of the element in order to ensure that the array of elements in order to be added to the number key, so that to confirm the removal of an element two do not change the key can see the green part, then how to solve it Just one line of code to fix

After foreach, add the

$arr = Array_values ($arr);

It's good to index the array again.

unset array Json_encode data format