js数组转换成json串 (JSON.stringify)

例如：

var giftlist[1490011777] = [];

giftlist[1490011777]['id'] = 1490011777;

giftlist[1490011777]['name'] = "礼包测试";

giftlist[1490011777]['desc'] = "详情";

转换json串

var jsonStr = JSON.stringify(giftlist[1490011777]);