在php中检查收到的索引继承

I'am searching the best way to do that test in php : So i have a list which contains numbers and I have to check the succesion of these numbers so if there is no succession it is necessary to announce an alert and to recover the missing index or the list of the missing indexes

So for example my array is like that:

Array ( [0] => 1 [1] => 2 [2] => 3 [3] => 4 [4] => 6 [5] => 9 )

Here my algorithm must returns missing indexes are : [5,7,8]

If you make a range of the min and max value then use array_diff that should give you the result you want.

$arr = []; // your array
$range = range(min($arr), max($arr));
var_export(array_diff($range, $arr));
// [5,7,8]

https://3v4l.org/0pE3o

If you sort the numbers

sort($numbers);

You can use a nested loop.

foreach ($numbers as $k => $x) {
    for ($n = $x + 1, $y = $numbers[$k + 1] ?? $x; $n < $y; $n++) {
        $missing[] = $n;
    }
}

The outer loop iterates the set of numbers, and the inner loop counts up from the current number to the next number.