php 数组里包含多个数组items解析成json方法:

$json_str = '{
"mid": "e34ed1c2d4",
"amount": 254,
"currency": "USD",
"external_order_id": "11",
"order_type": "GTC",
"application": "sed",
"version": "nostrud",
"checksum": "{checksum}",
"gateway": "KHFTBCRC3102",
"items": [
{
"currency":"USD",
"name": "Apple iPad with Retina",
"price": 55,
"quantity": 1
},
{
"currency":"USD",
"name": "Beats Solo Wireless",
"price": 199,
"quantity": 1
}],
"shipping_address": {
"first_name": "lin",
"last_name": "lastname",
"country": "DE",
"city": "hamburg city",
"address1": "this street address",
"postal_code": "10086",
"email": "10000@qq.com",
"phone": "12114569874",
"phone_country": "1",
"state": "Bayern"
},
"external_data": "test"
}';

echo "<hr/>";
echo "原始数据：";
var_dump($json_str);
echo "<pre/>";
$de_str = json_decode($json_str);
var_dump($de_str);
//die;

---------------------------------------------------

原始json数据：string(1057) "{
        "mid": "e34ed1c2d4",
        "amount": 254,
        "currency": "USD",
        "external_order_id": "11",
        "order_type": "GTC",
        "application": "sed",
        "version": "nostrud",
        "checksum": "{checksum}",
        "gateway": "KHFTBCRC3102",
        "items": [
        {
            "currency":"USD",
            "name": "Apple iPad with Retina",
            "price": 55,
            "quantity": 1
        },
        {
            "currency":"USD",
            "name": "Beats Solo Wireless",
            "price": 199,
            "quantity": 1
        }],
        "shipping_address": {
            "first_name": "lin",
            "last_name": "lastname",
            "country": "DE",
            "city": "hamburg city",
            "address1": "this street address",
            "postal_code": "10086",
            "email": "10000@qq.com",
            "phone": "12114569874",
            "phone_country": "1",
            "state": "Bayern"
        },
        "external_data": "test"
    }"

---------------------------------------------------
json_decode 后的数据格式：

object(stdClass)#1 (12) {
  ["mid"]=>
  string(10) "e34ed1c2d4"
  ["amount"]=>
  int(254)
  ["currency"]=>
  string(3) "USD"
  ["external_order_id"]=>
  string(2) "11"
  ["order_type"]=>
  string(3) "GTC"
  ["application"]=>
  string(3) "sed"
  ["version"]=>
  string(7) "nostrud"
  ["checksum"]=>
  string(10) "{checksum}"
  ["gateway"]=>
  string(12) "KHFTBCRC3102"
  ["items"]=>
  array(2) {
    [0]=>
    object(stdClass)#2 (4) {
      ["currency"]=>
      string(3) "USD"
      ["name"]=>
      string(22) "Apple iPad with Retina"
      ["price"]=>
      int(55)
      ["quantity"]=>
      int(1)
    }
    [1]=>
    object(stdClass)#3 (4) {
      ["currency"]=>
      string(3) "USD"
      ["name"]=>
      string(19) "Beats Solo Wireless"
      ["price"]=>
      int(199)
      ["quantity"]=>
      int(1)
    }
  }
  ["shipping_address"]=>
  object(stdClass)#4 (10) {
    ["first_name"]=>
    string(3) "lin"
    ["last_name"]=>
    string(8) "lastname"
    ["country"]=>
    string(2) "DE"
    ["city"]=>
    string(12) "hamburg city"
    ["address1"]=>
    string(19) "this street address"
    ["postal_code"]=>
    string(5) "10086"
    ["email"]=>
    string(12) "10000@qq.com"
    ["phone"]=>
    string(11) "12114569874"
    ["phone_country"]=>
    string(1) "1"
    ["state"]=>
    string(6) "Bayern"
  }
  ["external_data"]=>
  string(4) "test"
}

---------------------------------------------------
重点：数组直接转json方式：

---------------------------------------------------

//只把数组的内层转为object

function array_to_object3($arr) {
    if (gettype($arr) == 'array' ) {
        foreach ($arr as $k => $v) {
           if (gettype($v) == 'array') {
                $arr[$k] = (object)array_to_object3($v);
            }
        }
        return $arr;
    }else{
        return;
    }
}

$arrHashCode['items'] = array_to_object3($GoodsArr);
//注： 因为json_encode （把数组转json）只转化最外层的数组，内层的数组不能转，所以内层的数组要额外转object格式

$json_str=json_encode($arrHashCode);

================================================================================================
附：

// 数组转对象，全转化   
public function array_to_object($arr) {
    if (gettype($arr) == 'array' ) {       
    foreach ($arr as $k => $v) {
        if (gettype($v) == 'array' || getType($v) == 'object') {
            $arr[$k] = (object)$this->array_to_object($v);
        }
    }
       return (object)$arr;
    }elseif (getType($arr) == 'object') {
       return (object)$arr;
    }else{
       return;
    }
}

// 对象转数组

function object_to_array($obj){
    $_arr=is_object($obj)?get_object_vars($obj):$obj;
　　 //内排序
    //ksort($_arr);
    $arr = null;
    foreach($_arr as $key=>$val){
        $val=(is_array($val))||is_object($val)?object_to_array($val):$val;
        $arr[$key]=$val;
    }
    return $arr;
}
//数组转连接符

function array2String($arr = null){
    if(is_null($arr) or !is_array($arr))
        return false;
    $str = '';
    $arr_length = count($arr)-1;
    foreach( $arr as $key => $value ){
        if ($key=='checksum'){
            continue;
        }
        $type=gettype($value);
        if ($type=='array') {
            $tostr=json_encode($value);
            $str.=$key.'='.$tostr.'&';
        }else{
            $str.=$key.'='.$value.'&';
        }
    }
    return urldecode($str); // 必须使用urldecode()方法处理明文字符串
}