对于循环公式

I have the following and would want another result.

String = A,B,C,D

Trying to get an array of

A
A,B
A,B,C
A,B,C,D

My current code

 $arrayA = explode(',', $query);
                $arrSize = count($arrayA);

 for ($x=0; $x<$arrSize; ++$x) {
                    for ($y=0; $x==$y; ++$y) {
                        array_push($arrayB,$arrayA[$x]);
                        $y=0;
                    }
                }

Here's one way to do it using array_slice:

$str = 'A,B,C,D';

$strArr = explode(',', $str);

$newArr = array();

for($i=1; $i<=sizeof($strArr); $i++) 
{
  $newArr[] = implode( ',' , array_slice($strArr, 0, $i) );
}

print_r($newArr);

Outputs:

Array
(
    [0] => A
    [1] => A,B
    [2] => A,B,C
    [3] => A,B,C,D
)

Online demo here.

$test="a,b,c,d,e";
$arrayA = explode(',', $test);
$res=array();
$aux=array();
foreach($arrayA as $c){
    $aux[]=$c;
    $res[]=$aux;
}

i have not tested yet, but i think u catch the idea ;)