1.默认情况下  索引数组  返回的是数组 字符串

2关联数组  返回的是 对象字符串 

3.多维数组的情况

$a = [
["name"=>"ci","name1"=>"ci","name2"=>"ci","name3"=>"ci","name4"=>"ci"],
["name5"=>"ci","name6"=>"ci","name7"=>"ci","name8"=>"ci","name9"=>"ci"],
["name10"=>"ci","name11"=>"ci","name12"=>"ci","name13"=>"ci","name14"=>"ci"],
];
foreach ($a as $k => $v) {
   if($k ==0){
       unset($a[$k]);
   }
}
sort($a);（不排序 就是返回对象的形式,排了就是返回数组的形式）
var_dump( json_encode($a));