$a = '{"protocol":{"customerId":261320006,"channelId":25003782,"appKey":"C9454C2BBC9B307EA4BC2E93DCF6AE51"},"param":{"channelOrderId":"wx4053029330878697982","pin":"jd_QgTLxBafVVnm","productList":[{"mainSku":{"skuId":"4267819","skuPrice":20.52,"quantity":1,"skuName":"\u6768\u5927\u7237\u70df\u718f\u56db\u5ddd\u7279\u4ea7\u814a\u80a0\u814a\u5473\u9ebb\u8fa3\u9999\u80a0200g"}}],"orderFee":20.52,"freightFee":8,"address":{"provinceId":0,"cityId":0,"countyId":0,"townId":0,"fullAddress":"\u8fbd\u5b81\u7701\u76d8\u9526\u5e02\u5927\u6d3c\u53bf\u4e1c\u6e56\u80dc\u666fB\u533a11\u53f7\u697c1\u5355\u51431402","detailAddress":"\u8fbd\u5b81\u7701\u76d8\u9526\u5e02\u5927\u6d3c\u53bf\u4e1c\u6e56\u80dc\u666fB\u533a11\u53f7\u697c1\u5355\u51431402"},"receiver":{"receiverName":"\u90ed\u7d20\u6587","receiverMobile":"15042760575","receiverEmail":"liuchaojun@xiangleba.com.cn","zipCode":"000000"},"paymentType":2,"shipmentType":1,"channelOrderSource":"OTHER","sendGoods":1,"invoice":{"invoiceType":2,"vatInvoice":{"companyName":"\u5317\u4eac\u5723\u6cfd\u5929\u4e0b\u7f51\u7edc\u79d1\u6280\u6709\u9650\u516c\u53f8","code":"91110105MA01FGQ253","regAddr":"\u5317\u4eac\u5e02\u671d\u9633\u533a\u5341\u91cc\u5821\u75323\u53f7\u9662\u75321\u53f7\u697c3\u5c423-1-71","regPhone":"010-53821886","regBank":"\u4e2d\u56fd\u94f6\u884c\u5317\u4eac\u542f\u9633\u8def\u652f\u884c","regBankAccount":"332468509578","consigneeName":"\u5218\u8d85\u519b","consigneeMobile":"13501003805","vatAddress":{"vatProvinceId":0,"vatCityId":0,"vatCountyId":0,"vatTownId":0,"vatFullAddress":"\u5317\u4eac\u5317\u4eac\u5e02\u671d\u9633\u533a\u5341\u91cc\u5821\u4e07\u79d1\u65f6\u4ee3\u4e2d\u5fc3\u5341\u91cc4\u697c405"}}},"userIp":"127.0.0.1"}}';
$b = json_decode($a,1);
$b['param']['receiver']=iconv('gb2312','utf-8','丛文林转郭素文');
$c = json_encode($c);
var_dump($c)
为啥json_encode 结果是null啊
