sort方法

//默认排序，调用php的sort方法，失去原来的键名或索引值
$arr = A(['name'=>1,'age'=>4]);
print_r($arr->sort()); //[0=>1, 1=> 4]

//根据key排序
$arr = A(['name'=>1,'age'=>4]);
print_r($arr->sort('k')); //['age'=>4,'name'=>1]
print_r($arr->sort('-k')); //['name'=>1,'age'=>4]

//根据value排序
$arr = A(['name'=>1,'age'=>4]);
print_r($arr->sort('v')); //['name'=>1,'age'=>4]
print_r($arr->sort('-v')); //['age'=>4,'name'=>1]

//根据索引名排序，类似数据库根据字段名排序
$arr = A([['name'=>1,'age'=>4],['name'=>1,'age'=>3],['name'=>1,'age'=>2]]);
print_r($arr->sort('name,age')); //[['name'=>1,'age'=>2],['name'=>1,'age'=>3],['name'=>1,'age'=>4]]; 

//根据索引值排序
$arr = A([[1,4],[1,3],[1,2]]);
print_r($arr->sort('0,1')); //[[1,2],[1,3],[1,4]]; 

//自定义排序规则
$arr = A([1,4,2]);

$arr = $arr->sort(function($x, $y){
    if($x == $y){
        return 0;
    }
    return ($x < $y) ? -1 : 1;
});

print_r($arr);  //[1,2,4]