php array not saved in object

Question

I do not understand fully why this PHP code is not saving the data in the arrays. when I echo out the array during the while loop, the values are set but after I exit the loop, the values in the array are missing. The other variables did contain their values after leaving the array.

<?php
    class VIEWARRAY {
        public $year;
        public $month;
        public $day = array();
        public $views = array();
    }

    $viewdatabase = array();

    $connection = MySQL_Connection($host, Session_Get("username"), Session_Get("password"), $database);

    $dayviewindex = 0; $monthyearindex = 0; $previousmonth = "";
    $information = MySQL_Script($connection, "SELECT * FROM viewdatabase");
    while ($index = mysqli_fetch_array($information)) {
        if ($index["month"] != $previousmonth) {    
        $viewdatabase[$monthyearindex] = new VIEWARRAY;
        $viewdatabase[$monthyearindex]->year = $index["year"];
        $viewdatabase[$monthyearindex]->month = $index["month"];

            $dayviewindex = 0;
        $monthyearindex++;
        $previousmonth = $index["month"];
        }

        $viewdatabase[$monthyearindex]->day[$dayviewindex] = $index["day"];
        $viewdatabase[$monthyearindex]->views[$dayviewindex] = $index["views"];
        $dayviewindex++;
    }

    MySQL_Disconnect($connection);

    //testing area
    echo "->" . $viewdatabase[0]->year . " + " . $viewdatabase[0]->month . "<br />"; //prints out ->2013 + 8
    echo "------>" . $viewdatabase[0]->day[2] . " + " . $viewdatabase[0]->views[2] . "<br />"; //prints out ------> + 
    echo count($viewdatabase[0]->views) . "<br />"; //prints out 0
    echo count($viewdatabase[1]->views) . "<br />"; //prints out 0

    ?>

I made sure that I was able to connect to my database just fine and that my database did return information. This is how my database is setup

year     month     day     views
2013     8         25      1
2013     8         26      1
2013     8         27      1
2013     9         3       1

Answer 1

At first run, after if ($index["month"] != $previousmonth), $monthyearindex will be 1. That means you'll next try to access $viewdatabase[1] but it's NULL. On the next iteration you won't enter the if, $monthyearindex will be 1, and $viewdatabase[1] will still be NULL. So you never actually get to set anything in day and views.

Answer 2

Use

if ($index["month"] !== $previousmonth) {

instead of

if ($index["month"] != $previousmonth) {

, because

0 == ''

, but

0 !== ''

. Because,

$index['month'] != ''

is

false

, your if statement fails.