PHP按二维数组中的某个值重新排序数组 usort的使用方法

$arr[0] = ['aa'=>123,'bb'=>'abc'];
$arr[1] = ['aa'=>456,'bb'=>'dfe'];
usort($arr,ss('aa'));
function ss($key){
    return function ($a,$b) use ($key) {
        return $a[$key] < $b[$key];     //通过改变大于、小于来正向反向排序
    };
}
var_dump($arr);

/*
* 结果
array (size=2)
  0 =>
    array (size=2)
      'aa' => int 456
      'bb' => string 'dfe' (length=3)
  1 =>
    array (size=2)
      'aa' => int 123
      'bb' => string 'abc' (length=3)
*/

<?php

$arr = array(
    0 => array('id' => '2014347856', 'name' => '张甜', '科目' => '语文', 'tag' => '期中考试', '成绩' => '142'),
    1 => array('id' => '2014347856', 'name' => '张甜', '科目' => '数学', 'tag' => '期中考试', '成绩' => '98'),
    2 => array('id' => '2014347856', 'name' => '张甜', '科目' => '英语', 'tag' => '期中考试', '成绩' => '118'),
    3 => array('id' => '2014347856', 'name' => '张甜', '科目' => '化学', 'tag' => '期中考试', '成绩' => '78'),
    4 => array('id' => '2014347856', 'name' => '张甜', '科目' => '物理', 'tag' => '期中考试', '成绩' => '132'),
    5 => array('id' => '2014347856', 'name' => '张甜', '科目' => '生物', 'tag' => '期中考试', '成绩' => '115'),
    6 => array('id' => '2014347856', 'name' => '张甜', '科目' => '地理', 'tag' => '期中考试', '成绩' => '99'),
    7 => array('id' => '2014347856', 'name' => '张甜', '科目' => '历史', 'tag' => '期中考试', '成绩' => '88'),
    8 => array('id' => '2014347856', 'name' => '张甜', '科目' => '政治', 'tag' => '期中考试', '成绩' => '125'),
    9 => array('id' => '2014347880', 'name' => '李鸣', '科目' => '语文', 'tag' => '期中考试', '成绩' => '79'),
    10 => array('id' => '2014347880', 'name' => '李鸣', '科目' => '数学', 'tag' => '期中考试', '成绩' => '148'),
    11 => array('id' => '2014347880', 'name' => '李鸣', '科目' => '英语', 'tag' => '期中考试', '成绩' => '142'),
);
/*自定义排序*/
function userSort($a, $b)
{
    if ($a['name'] == $b['name']) {
        /*排序科目*/
        $subjectSort = array('语文', '数学', '英语', '历史', '政治', '地理', '物理', '化学', '生物');
        foreach ($subjectSort as $index => $item) {
            if ($a['科目'] == $item) {
                $tmp1 = $index;
            }
            if ($b['科目'] == $item) {
                $tmp2 = $index;
            }
        }

        return $tmp1 < $tmp2 ? -1 : 1;
    } else {
        /*排序name*/
        $tmpArr = array($a['name'], $b['name']);
        sort($tmpArr);

        return $a['name'] == $tmpArr[0] ? -1 : 1;
    }
}

usort($arr, 'userSort');

var_dump($arr);