dynamic variables from array - php

Question

I store the field names within an array, in hopes to dynamically create the variables.
I receive a illegal offset type error for the if and else, these two lines:
$data[$tmp_field] = $tmp_field[$id];
$data[$tmp_field] = 0;
I checked the post data and it is posting with the appropriate data, but I am not sure what the problem is.
$student_id stores all the students ids., for example: $student_id = array(8,9,11,23,30,42,55);
function updateStudentInfo() {
$student_id = $this->input->post('student_id');
$internet_student = $this->input->post('internet_student');
$dismissed = $this->input->post('dismissed');
$non_matriculated_student = $this->input->post('non_matriculated_student');
$felony = $this->input->post('felony');
$probation = $this->input->post('probation');
$h_number = $this->input->post('h_number');
$office_direct_to = $this->input->post('office_direct_to');
$holds = $this->input->post('holds');
$fields = array('internet_student', 'non_matriculated_student', 'h_number', 'felony', 'probation', 'dismissed');
foreach($student_id as $id):
$data = array();
foreach($fields as $field_name):
$tmp_field = ${$field_name};
if(empty($tmp_field[$id])) {
$data[$tmp_field] = 0;
} else {
$data[$tmp_field] = $tmp_field[$id];
}
endforeach;
print '<pre style="color:#fff;">';
print_r($data);
print '</pre>';
endforeach;
}
This is the array format I desire:
Array
(
[internet_student] => 1
[non_matriculated_student] => 1
[h_number] => 0
[felony] => 0
[probation] => 1
[dismissed] => 0
)
Added screenshot to give you a visual of the form the data is being posted from

Answer 1

foreach($student_id as $id):
$data = array();
foreach($fields as $field_name):
$tmp_field = ${$field_name};
if(empty($tmp_field[$id])) {
$data[$field_name] = 0;
} else {
$data[$field_name] = $tmp_field[$id];
}
endforeach;
print '<pre style="color:#fff;">';
print_r($data);
print '</pre>';
endforeach;

Answer 2

I am assuming that all these fields are arrays, as otherwise you wouldn't need any loops.
function updateStudentInfo()
{
$student_id = $this->input->post('student_id');
$internet_student = $this->input->post('internet_student');
$dismissed = $this->input->post('dismissed');
$non_matriculated_student = $this->input->post('non_matriculated_student');
$felony = $this->input->post('felony');
$probation = $this->input->post('probation');
$h_number = $this->input->post('h_number');
$office_direct_to = $this->input->post('office_direct_to');
$holds = $this->input->post('holds');
$fields = array('internet_student', 'non_matriculated_student', 'h_number', 'felony', 'probation', 'dismissed');
$student_count = count($student_id);
foreach($student_id as $id)
{
$data = array();
foreach($fields as $field)
{
if(array_key_exists($id, $$field))
$data[$field] = ${$field}[$id];
}
}
}
You are trying to use the student id as an array key for the other fields but the HTML form is just a standard indexed array, not keyed to any student data.