# your initial definitions here

# maybe a loop starts here
my $student;  # single student
my @students; # all students in 1 class

$student = {
    studentName => 'John',
    studentSurname=>'Something',
    studentID=>'9534',
    age=>'12'
};
push @students, $student;

# Eliminate loading next student below explicitly
# by using a loop to read from source file, DB, etc.
$student = {
    studentName => 'Mary',
    studentSurname=>'Something2',
    studentID=>'5489',
    age=>'13'
};
push @students, $student;

%classroom = (
    classroomID => 10,
    classroomName => 'classroom1',
    students => \@students
);

# Rinse, repeat