$obj->0

w对象 数组 分别对内存的 消耗

CI result()

This method returns the query result as an array of objects, or an empty array on failure. 

http://stackoverflow.com/questions/9474446/get-first-element-in-php-stdobject

<?php
$obj = new StdClass;
for ($w = 0; $w < 4; $w++) {
    $obj->$w = $w;

}
$obj->www = 123;

echo $obj->www;

echo $obj->{0};
var_dump($obj);
//var_dump($obj->'0');

$obj->0;

$obj->'0';

$obj->"0";

$obj->{0};

Parse error: syntax error, unexpected T_LNUMBER, expecting T_STRING or T_VARIABLE or '{' or '$'