check value available in array and add then add more with previous php code example
Example 1: php append to array
$myArr = [1, 2, 3, 4];
array_push($myArr, 5, 8);
print_r($myArr); // [1, 2, 3, 4, 5, 8]
$myArr[] = -1;
print_r($myArr); // [1, 2, 3, 4, 5, 8, -1]
Example 2: php add to array
$fruits = ["apple", "banana"];
// array_push() function inserts one or more elements to the end of an array
array_push($fruits, "orange");
// If you use array_push() to add one element to the array, it's better to use
// $fruits[] = because in that way there is no overhead of calling a function.
$fruits[] = "orange";
// output: Array ( [0] => apple [1] => banana [2] => orange )