Inserting several items from array to database with `foreach`

I want to insert several items from an array into a database with foreach. I get an error Message: Undefined offset. Can someone help me figure out what's causing it?

error:

A PHP Error was encountered
Severity: Notice
Message: Undefined offset: 0
Line Number: 127

A PHP Error was encountered
Severity: Notice
Message: Undefined offset: 0
Line Number: 128

A PHP Error was encountered
Severity: Notice
Message: Undefined offset: 0
Line Number: 129

php:

<?php

$guide_input = $this->input->post('guide');
$airline_input = $this->input->post('airline');

$name_r_input = $this->input->post('name_r');
$units_input = $this->input->post('units');
$price_change_input = $this->input->post('price_change');

$guide = array();
$airline = array();
$date_go = array();
$date_back = array();
$residence = array();
foreach ($guide_input as $idx => $name) {
    $guide[] = array(
        'name_guide' => $guide_input[$idx], //Line Number: 121
    );
    $airline[] = array(
        'name_airline'开发者_如何学编程 => $airline_input[$idx], //Line Number: 124
    );
    $residence[] = array(
        'name_r' => $name_r_input[$idx], //Line Number: 127
        'units' => $units_input[$idx], //Line Number: 128
        'price_change' => $price_change_input[$idx], //Line Number: 128
    );
};
$data = array(
    'json1' => json_encode($residence),
    'json2' => json_encode($airline),
    'json3' => json_encode($guide),
);

$this->db->insert(tableName, $data);

---

above code assumes that all input arrays like $airline_input, $date_go_input and so on.. will have the same number of elements as $guide_input in them. My guess is they dont.

For the code to be correct and run without errors yu should check:

count($guide_input) == count($airline_input)
&& count($guide_input) == count($date_go_input)
// ... and so on... //

---

I think you should check guide_input, airline_input, and so on. Every arrays has same keys?