用PHP返回数组的最后一个值

I have an array that is used later used by jquery to plot a chart (hence the json_encode).

<?php   
    $server = "myserver:1234";
    $user="dbuser";
    $password="userpass";  
    $database = "dbname";

    $connection = mysql_connect($server,$user,$password);
    $db = mysql_select_db($database,$connection);

    $query = "SELECT Y FROM listener_incr";

    $result = mysql_query($query);        

    $i = -60;

    while($row = mysql_fetch_assoc($result))
    {
        $dataset1[] = array($i,$row['Y']);
        $i++;
    }
    $final = json_encode($dataset1,JSON_NUMERIC_CHECK);    
?>  

The output of $final is [[-60,5],[-59,3],[-58,6],...[-1,7],[0,8]]

Aside from the data series being used to plot a chart, I want to echo the last value of my array to a div.

Here is what I have tried...

<div id="LastInArray">
  Current count: <?php
   end($dataset1);
   $intOutput = key($dataset1);
   echo $intOutput;
  ?>
</div>

But the above outputs Current count: 59, which I don't understand. The output I want for the div (in this example) is Current count: 8.

Later I want to use AJAX to update this value, which is why it's in a div.

end() doesn't traverse your multi-dimensional array iirc. For your value something like $dataset1[count($dataset1)-1][1] should be enough.

Use array_pop Check the documentation http://php.net/manual/en/function.array-pop.php

$tmp = current($dataset1); // return [-1, 8]
$intOutput = $tmp[1];  // return 8

You can always count() the number of records in the array and then access its last record with count()-1.

I would suggest you to find out the JSON length first and then using length-1 as key, you can get the value out of key-value pair in JSON.