Array Comparison

[Fleshgrinder]

In note 5. about array comparisons the following is stated:

If the next key in the left-hand operand does not exist in the right-hand operand, the arrays cannot be compared and FALSE is returned.

This is actually not true in case of the spaceship operator on both PHP and HHVM.

<?php

$lhs = [0 => 0];
$rhs = [1 => 1];

var_dump(
    $lhs < $rhs,
    $lhs <= $rhs,
    $lhs <=> $rhs,
    $lhs >= $rhs,
    $lhs > $rhs
);

/*
bool(false)
bool(false)
int(1)
bool(false)
bool(false)
*/

[bradynpoulsen]

Good find, that should probably read: If the next key in the left-hand operand does not exist in the right-hand operand, the arrays cannot be compared and are considered not equal.

The spaceship operator is designed to do a bi-directional comparison. Meaning not only does it report if they are equal or not, it also specifies whether it's greater than or less than. The spaceship operator always returns an integer representing those details (similar to strcmp).

See: http://php.net/manual/en/language.operators.comparison.php