php - 按子数组排序多维数组

Question

我有以下数组，我试图按分数排序，然后匹配，然后是名称，但我的方法不起作用。谁能明白为什么？

最终顺序应该是 4、3、5。

我使用的usort是在底部。

        [3] => Array
            (
                [name] => DrayTek Vigor 2130Vn VoIP/WiFi Router
                [matches] => Array
                    (
                        [0] => voip
                    )
                [score] => 3
            )
        [4] => Array
            (
                [name] => DrayTek Vigor 2750n VDSL Wireless Router
                [matches] => Array
                    (
                        [0] => 2750
                    )
                [score] => 3
            )
        [5] => Array
            (
                [name] => DrayTek Vigor 2850Vn VDSL/ADSL VoIP Router
                [matches] => Array
                    (
                        [0] => voip
                    )
                [score] => 3
            )

逻辑

1. all have the same score, so no change in order 
2. 4 has 2750 in matches[0] which assuming numbers come before letters, moves 4 up
** the order now should be 4,3,5
3. as 3 and 5 have the same matches[], no change in order
4. 3's name naturally comes before 5 but since its already above, no change
** final order should be 4,3,5

排序结果，最高分优先，然后匹配数组，然后是名称

function cmp($a, $b)
{
    if ( $a['score'] < $b['score'] )
        return 1;
    elseif ( $a['score'] > $b['score'] )
        return -1;
    elseif ( ! array_diff( $a['matches'], $b['matches'] ) )
        return 1;
    elseif ( ! array_diff( $b['matches'], $a['matches'] ) )
        return -1;
    elseif ( ($c = strnatcmp( strtolower($a['name']), strtolower($b['name']) ) ) !== 0 )
        return $c;
    else
        return 0;
}
usort( $this->results['rows'], "cmp" );

Answer 1

您似乎对匹配数组比较有反转的感觉（如果它们相等，则返回 1，而不是返回 0/让它通过下一个测试）。因为当它们不相等时你需要一个明确的顺序，也许你应该按匹配数组的长度排序：

function cmp($a, $b)
{
    # sort by score 
    $result = $b['score'] - $a['score'];

    # then by number of matches
    if ($result == 0) {
      $result = count($b['matches']) - count($a['matches']);
    }

    # if they have the same number of matches but different matches, who wins?
    if ($result == 0) {
      $result = strnatcasecmp($a['name'], $b['name']);
    }

    return $result;
}

问题array_diff在于它返回一个数组。您将该结果与什么进行比较以获得 a 和 b 的排序？比较函数需要能够在没有任何其他上下文的情况下从数组的其余部分订购任意两项。

Answer 2

找到了解决方案

function cmp($a, $b)
{
    if ( $a['score'] < $b['score'] )
        return 1;

    if ( $a['score'] > $b['score'] )
        return -1;

    if ( count( $a['matches'] ) > count( $b['matches'] ) )
        return 1;

    if ( count( $a['matches'] ) < count( $b['matches'] ) )
        return -1;

    natsort( $a['matches'] );   natsort( $b['matches'] );

    for ( $i = 0; $i < count( $a['matches'] ); $i++ )
    {
        if ( ( $c = strnatcasecmp( $b['matches'][$i], $a['matches'][$i] ) ) !== 0)
            return $c;
    }

    if ( ( $c = strnatcasecmp( strtolower($a['name'] ), strtolower( $b['name'] ) ) ) !== 0 )
        return $c;

    return 0;
}

usort( $this->results['rows'], "cmp" );