<?php
$data = array('name'=>'fdipzone');
echo json_encode($data);            // {"name":"fdipzone"}
print_r(json_decode(json_encode($data), true)); //Array ( [name] => fdipzone )
?>

<?php
$str = '{"name":"fdipzone"}';
var_dump(json_decode($str, true)); // array(1) { ["name"]=> string(8) "fdipzone" }

$str1 = '{name:"fdipzone"}';
var_dump(json_decode($str1, true)); // NULL
?>

<?php
/** 兼容key没有双引括起来的JSON字符串解析
* @param String $str JSON字符串
* @param boolean $mod true:Array,false:Object
* @return Array/Object
*/
function ext_json_decode($str, $mode=false){
  if(preg_match('/\w:/', $str)){
    $str = preg_replace('/(\w+):/is', '"$1":', $str);
  }
  return json_decode($str, $mode);
}

$str = '{"name":"fdipzone"}';
var_dump(ext_json_decode($str, true)); // array(1) { ["name"]=> string(8) "fdipzone" }

$str1 = '{name:"fdipzone"}';
var_dump(ext_json_decode($str1, true)); // array(1) { ["name"]=> string(8) "fdipzone" }
?>