问题描述

对数组进行排序，先对a字段正序排序，但0排到最后，再对b字段逆序排序

实现代码

// 对数组进行排序，先对a字段正序排序，但0排到最后，再对b字段逆序排序
$a1 = array(
    array('a' => 1,'b' => 1),
    array('a' => 2,'b' => 1),
    array('a' => 1,'b' => 2),
    array('a' => 0,'b' => 1),
    array('a' => 1,'b' => 3),
    array('a' => 2,'b' => 2),
    array('a' => 0,'b' => 2),
    array('a' => 2,'b' => 3)
);

// 对a排序
function my_sort1($a,$b) {
    if ($a['a'] == 0) {
        return 1;
    }
    if ($b['a'] == 0) {
        return -1;
    }
    if ($a['a'] > $b['a']) {
        return 1;
    }
    return -1;
}

// 对b排序
function my_sort2($a,$b) {
    if ($a['a'] == $b['a']) {
        if ($a['b'] < $b['b']) {
            return 1;
        } elseif ($a['b'] > $b['b']) {
            return -1;
        }
    }
    return 0;
}

usort($a1,"my_sort1");
usort2($a1,"my_sort2");

返回结果

php7.2返回结果正常
Array
(

[0] => Array
    (
        [a] => 1
        [b] => 3
    )

[1] => Array
    (
        [a] => 1
        [b] => 2
    )

[2] => Array
    (
        [a] => 1
        [b] => 1
    )

[3] => Array
    (
        [a] => 2
        [b] => 3
    )

[4] => Array
    (
        [a] => 2
        [b] => 2
    )

[5] => Array
    (
        [a] => 2
        [b] => 1
    )

[6] => Array
    (
        [a] => 0
        [b] => 2
    )

[7] => Array
    (
        [a] => 0
        [b] => 1
    )

)
php5.6返回结果有问题
Array
(

[0] => Array
    (
        [a] => 0
        [b] => 2
    )

[1] => Array
    (
        [a] => 0
        [b] => 1
    )

[2] => Array
    (
        [a] => 2
        [b] => 3
    )

[3] => Array
    (
        [a] => 2
        [b] => 2
    )

[4] => Array
    (
        [a] => 2
        [b] => 1
    )

[5] => Array
    (
        [a] => 1
        [b] => 3
    )

[6] => Array
    (
        [a] => 1
        [b] => 2
    )

[7] => Array
    (
        [a] => 1
        [b] => 1
    )

)

思考

**查阅了相关信息，函数php7并没有修改usort方法
疑问：是否php7版本对php数组进行了修改
如果有大神知道的，还望不吝赐教！**