Question

<?php
$bigArray = array(
    array('John','2012-03-29',1),
    array('Doe','2012-03-30',1),
    array('John','2012-03-31',2),
    array('Doe','2012-03-31',5),
    array('Tom','2012-03-31',5),
    array('John','2012-04-02',5),
    array('John','2012-04-02',21),
    array('John','2012-03-07',21)
);

$cache = array();
foreach ($bigArray as $v) {
    if (isset($cache[$v[1]])) {
        if ($cache[$v[1][1]] == $v[2]) {
            echo "Equal";
            $cache[$v[1]] = array($v[0].','.$cache[$v[1]][0], $v[2]);//append user to same value
        }
        else if ($cache[$v[1][1]] < $v[2]) {
            echo "Replacing value! ".$cache[$v[1]][0]. " to " .$v[0]."<br/>";
            $cache[$v[1]] = array($v[0], $v[2]);
        }
    } else {
        $cache[$v[1]] = array($v[0], $v[2]);
    }
}

print_r($cache);
?>

This script finds the highest value for a particular date and saves it to a new array $cache

However when checking if the highest value is equal on the same date, it returns false?

array(
    array('Doe','2012-03-31',5),
    array('Tom','2012-03-31',5),
)

The above in the array is what is confusing me. Shouldn’t it be counted as a match?

The output:

Replacing value! John to Doe
Replacing value! Doe to Tom
Replacing value! John to John
Array
(
    [2012-03-29] => Array
    (
        [0] => John
        [1] => 1
    )
    [2012-03-30] => Array
        (
        [0] => Doe
        [1] => 1
    )
    [2012-03-31] => Array
    (
        [0] => Tom
        [1] => 5
    )
    [2012-04-02] => Array
    (
        [0] => John
        [1] => 21
    )
    [2012-03-07] => Array
    (
        [0] => John
        [1] => 21
    )
)

Answer 1

Without going into too much detail, $v[1][1] seems to be quite nonsensical to me. It refers to the second character of the date string in your original array. You probably mean:

$cache[$v[1]][1]