在NSMutableArray中过滤JSON项

Question

我有一点问题，我有一个json feed，我想在数组中显示那些Country = France的项目怎么办？谢谢你（Objective-C）
我的JSON：

    { 
  "menu": "Fichier", 
  "commandes": [ 
      {
          "country": "France", 
          "city": "Paris"
      }, 
      {
          "country": "USA", 
          "city": "New York"
      }, 
      {
          "country": "Canada",
          "city": "Quebec"
      }
   ] 
} 

Answer 1

首先使用NSJSONSerialization解析您的JSON数据

// data will be your Json NSData

 NSError* jsonError;
 NSDictionary* jsonDictn = [NSJSONSerialization JSONObjectWithData:data
                             options:kNilOptions
                             error:&error];
 NSMutableArray * aray = [[jsonDictn objectForKey:@"commandes"] mutableCopy];
 for (NSDictionary* tmpdictn in aray) {
     NSString * tmpstr = [tmpdictn objectForKey:@"country"];
     if (![tmpstr isEqualToString:@"France"]) {
         [aray removeObject:tmpdictn];
      }
 }
 NSLog(@"aray: %@",aray);

Answer 2

这会有所帮助：

NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"commandes" ascending:TRUE];
[sourceArr sortUsingDescriptors:[NSArray arrayWithObjects:sortDescriptor, nil]];

Answer 3

您需要使用NSPredicate来搜索数组中的数据

使用下面的代码

NSPredicate *predicate = [NSPredicate predicateWithFormat:@"country == %@", @"France"];
NSArray *filteredArray = [[arr objectForKey:@"commandes"] filteredArrayUsingPredicate:predicate];