Is there another way to automatically increment student numbers? - php

Question

I am trying to automatically create student IDs and the ID looks like this "MILE/001/5". The 'mile' is the school name and the '001' is the class number and the '5' is the ID. There can only be 40 students in one class and after 40 the next student will go to the second class e.g 'Mile/002/41'. I have done this using hard coded if stemements meaning i stopped somewhere but i want to automatically do this in a few lines of code without all the if statements. I am getting the $count variable from the database and i increment it after each registered student. Here is the code:
if ($count <= 40) {
$class = '001';
$student_id = "MILE/".$class."/".$count;
} elseif($count >= 41 && $count <= 80 ) {
$class = '002';
$student_id = "MILE/".$class."/".$count;
} elseif($count >= 81 && $count <= 120 ) {
$class = '003';
$student_id = "MILE/".$class."/".$count;
} elseif($count >= 121 && $count <= 160 ) {
$class = '004';
$student_id = "MILE/".$class."/".$count; } }

Answer 1

Check out intdiv https://www.php.net/manual/en/function.intdiv.php
It will perform an integer division (discards fractional part), i.e. 1/2 => 0, 3/2 => 1.
Here's an implementation using intdiv
function generateId($school, $capacity, $id) {
$classIndex = intdiv($id - 1, $capacity) + 1;
$class = sprintf("%03d", $classIndex);
return "$school/$class/$id";
}
$CLASS_CAPACITY = 40;
$SCHOOL = 'MILE';
for ($id=38; $id < 42; $id++) {
$studentId = generateId($SCHOOL, $CLASS_CAPACITY, $id);
var_dump($studentId);
}
output:
string(11) "MILE/001/38"
string(11) "MILE/001/39"
string(11) "MILE/001/40"
string(11) "MILE/002/41"