Description:
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---
From manual page: http://www.php.net/language.operators.comparison
---
I feel array comparison "standard_array_compare" mentioned in this page need correction. 

If  "!array_key_exists($key, $op2)" returns "null", then "count($op1) < count($op2)" and "count($op1) > count($op2)" should both return "null". If the length of arrays do not match then either of them contain atleast 1 key different / additional than other. Is that right? 

One more observation and comment => comparison is non-type based for Key values, but larger question is should "null" be returned considering difference Key values? Do we consider that both arrays are of different types when "Key" values do not match?

Anyway, depends on the particular need and interpretation, but we can also say that function returns "null" as 2 arrays are non-comparable when Keys do not match.

So, in my view array comparison function should be =>
==================
<?php
// Arrays are compared like this with standard comparison operators
function standard_array_compare($op1, $op2)
{
    if (count($op1) < count($op2) || count($op1) > count($op2)) {
        return null; // uncomparable
    }
    foreach ($op1 as $key => $val) {
        if (!array_key_exists($key, $op2)) {
            return null; // uncomparable
        } elseif ($val < $op2[$key]) {
            return -1;
        } elseif ($val > $op2[$key]) {
            return 1;
        }
    }
    return 0; // $op1 == $op2
}
?>  

Test script:
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Same as example above