PHP中一些常用知识点

1、json字符串转json对象

$data='[{"user_id":"93","price":"52.50"},{"user_id":"93","price":"52.50"},{"user_id":"93","price":"52.50"}]';
$jsonObj = json_decode($data,true);
var_dump($jsonObj);

输出如下：

array (size=3)
  0 => 
    array (size=2)
      'user_id' => string '93' (length=2)
      'price' => string '52.50' (length=5)
  1 => 
    array (size=2)
      'user_id' => string '93' (length=2)
      'price' => string '52.50' (length=5)
  2 => 
    array (size=2)
      'user_id' => string '93' (length=2)
      'price' => string '52.50' (length=5)

这种输出方法与下面的一样：

 $sql = "SELECT * " ."FROM goods WHERE is_hot = 1";
 $row = $GLOBALS['db']->getAll($sql);
 var_dump($row);

输出如下：

array (size=10)
  0 => 
    array (size=52)
      'goods_id' => string '1089' (length=4)
      'cat_id' => string '310' (length=3)
      'goods_sn' => string 'ECS001201' (length=9)
      'goods_name' => string '喇叭袖中长上衣夏季短袖T恤打底裙' (length=86)
     
  1 => 
    array (size=52)
      'goods_id' => string '1099' (length=4)
      'cat_id' => string '336' (length=3)
      'goods_sn' => string 'ESCOO1105' (length=9)
      'goods_name' => string '榄油菜籽油玉米植物调和油商超同款' (length=86)
    
  2 => 
    array (size=52)
      'goods_id' => string '1110' (length=4)
      'cat_id' => string '336' (length=3)
      'goods_sn' => string 'ECS001110' (length=9)
      'goods_name' => string '自榨菜油5l食用油非转基因粮油' (length=88)