从服务器获取到的数据或提交到服务器的数据有可能是nil，那我们是否需要对需要用到的每个数据都判断其是否为nil呢？
如果是的话，会不会有些繁琐？ 尤其是当从服务器返回的数据或提交到服务器的数据比较多的时候。问一下该怎么保证
程序的健壮性同时又不让程序变得很臃肿。
这是我的从服务器获取数据的代码片段
NSDictionary *data = responseObject[@"data"];
NSArray *list = data[@"list"];
//这个数组用于用户点击苗木列表时，给苗木详情页面传值
if (_pageIndex == 1) {
self.sapArr = [NSMutableArray arrayWithArray:list];
}else{
for (NSDictionary *item in list) {
[self.sapArr addObject:item];
}
}
for (NSDictionary *item in list) {
HDNurseryItemModel *itemModel = [[HDNurseryItemModel alloc] init];
itemModel.itemID = item[@"_id"];
NSArray *imgArr = item[@"images"];
if (imgArr.count > 0) {
itemModel.iconName = imgArr[0];
}
itemModel.specID = [item objectForKey:@"specId"];
NSString *mainSpec = [Util decodeSapType:[itemModel.specID integerValue]];
NSInteger specMax = [[item objectForKey:@"specMax"]integerValue];
NSInteger specMin = [[item objectForKey:@"specMin"]integerValue];
NSInteger wocID = [[item objectForKey:@"planting"]integerValue];
NSString *woc = [Util decodeWOC:wocID];
//规格值
NSString *finalSpec = [Util combineSpec:mainSpec specMax:specMax specMin:specMin];
itemModel.loginName = item[@"loginName"];
itemModel.nickName = item[@"supplyLinkman"];
itemModel.leftTitle = finalSpec;
itemModel.rightTitle = woc;
itemModel.describe= item[@"spec"];
itemModel.price = [item[@"price"]floatValue] ;
itemModel.stock = [item[@"quantity"] intValue];
itemModel.addr = [NSString stringWithFormat:@"%@ %@",item[@"province"],item[@"city"]];
itemModel.city = item[@"city"];
itemModel.province = item[@"province"];
itemModel.spec = item[@"spec"];
itemModel.specID = item[@"specId"];
itemModel.specMax = item[@"specMax"];
itemModel.specMin = item[@"specMin"];
itemModel.treeID = item[@"treeId"];
itemModel.treeName = item[@"treeName"];
itemModel.nurseryID = item[@"nurseryId"];
itemModel.nurseryName = item[@"nurseryName"];
itemModel.planting = item[@"planting"];
itemModel.supplyflag = [item[@"supplyflag"] integerValue];
[_dataSource addObject:itemModel];这是提交到服务器的函数的代码片段
NSString *treeID = realTarget.model.treeID;
NSString *treeName = realTarget.model.treeName;
NSString *specMin = realTarget.model.specMin;
NSString *specMax = realTarget.model.specMax;
NSString *spec = realTarget.model.spec;
NSString *planting = realTarget.model.planting;
NSString *price = [NSString stringWithFormat:@"%.2f",realTarget.model.price] ;
NSString *quantity =[NSString stringWithFormat:@"%d",realTarget.model.stock] ;
NSString *nurseryID = realTarget.model.nurseryID;
// NSString *nurseryName = realTarget.model.nurseryName;
NSString *specID = realTarget.model.specID;
NSString *city = realTarget.model.city;
NSString *province = realTarget.model.province;
NSString *seedlingID = realTarget.model.itemID;
NSString *type = @"1";
NSString *loginName = [Util getLoginNameFromUserDefault];
NSString *nickName = [Util getNickNameFromUserDefault];
NSString *userID = [Util getUserIDFromUserDefault];
NSDictionary *param = [NSDictionary dictionaryWithObjects:@[userID,treeID,treeName,specMin,specMax,spec,planting,price,quantity,nurseryID,loginName,nickName,specID,city,province,type,seedlingID] forKeys:@[@"ym.memberId",@"ym.treeId",@"ym.treeName",@"ym.specMin",@"ym.specMax",@"ym.spec",@"ym.planting",@"ym.price",@"ym.quantity",@"ym.nurseryId",@"ym.pLoginName",@"ym.pNickName",@"ym.specId",@"ym.city",@"ym.province",@"ym.type",@"ym.seedlingId"]];
NSLog(@"param:%@",param);首先，后端对参数是一定要检验的，而且不只是检验nil的问题，“SQL注入”等等安全问题都是要考虑的。
IOS发参数，如果逻辑正确，参数的来源可信，就不需要多余的检验，但是基本的检验还是要有的。
IOS对服务器返回的数据应该也有基本的检验，至少服务器跪掉、报错、数据异常都是可能的。
服务器返回数据，应该区分有正常和异常的数据情况吧。
诸如此类，程序的健壮性，项目的质量，程序员的个人追求……
臃肿或者单纯……
……
json 序列化之后续费这么几种形式：
NSNumber
NSDictionary
NSArray
NSString
NSNull
由于OC对nil的友好，
你反序列化的时候，nil是不会有什么问题的。
NSNumber 是nil的话，就是0
NSDictionary，NSArray，NSString，NSNull就是nil，
不过你序列化的时候要注意，
NSArray, NSDictionary组装的时候不能有nil，你要保证这个的话，可以在addObject，setObject:forKey: 这些方法前做一些判断即可。
https://github.com/CoderMJLee/MJExtension