为foreach()提供的参数无效

Question

如何修复Message: Invalid argument supplied for foreach() - Line Number: 28以下错误foreach？

<?php
$mileage = array();
$mileage_input = $this->input->post('mileage');
foreach ($mileage_input as $idx => $name) {  //Line 28
    $mileage[] = array(
        'mileage' => $mileage_input[$idx]
    );
}
$data = array(
    'mileage' => json_encode($mileage),
    'customer_number' => $customer_number,
    'name' => $this->input->post('name')
);
$this->db->insert('customer', $data);
?>

Answer 1

$mileage_input 可能不是一个数组,这就是为什么它不起作用.