如何将整数范围转换为PHP数组[重复]

I'm trying to convert these integers/numbers:

$groups = '1707,1723,1733,16254,16256,18704,19792,29268,34956';

into an array in PHP array:

array("1707","1723","1733","29268","34956");

I'm using this

 $tags = array();
 foreach($groups as $index){
     array_push($tags, $index);
  }

But keep getting the below error.

 Error: Invalid argument supplied for foreach()

</div>

simple explode call:

$array=explode(',',$groups);

The explode() function breaks a string into an array.

$groups = '1707,1723,1733,16254,16256,18704,19792,29268,34956';
print_r(explode(",",$groups));