如何過濾多維陣列

Question

我有以下多維陣列（剝離並減小爲清楚起見）

[ 
    { 
     "type": "type1", 
     "docs": [ 
      { 
       "language": "EN" 
      }, 
      { 
       "language": "DE" 
      }, 
      { 
       "language": "EN" 
      } 
     ] 
    }, 
    { 
     "type": "type2", 
     "docs": [ 
      { 
       "language": "EN" 
      } 
     ] 
    }, 
    { 
     "type": "type3", 
     "docs": [ 
      { 
       "language": "FR" 
      }, 
      { 
       "language": "DE" 
      }, 
      { 
       "language": "DE" 
      } 
     ] 
    } 
] 

欲過濾它，所以只有文檔與DE的語言對象被示出。換句話說，我需要這樣的：

[ 
    { 
     "type": "type1", 
     "docs": [ 
      { 
       "language": "DE" 
      } 
     ] 
    }, 
    { 
     "type": "type2", 
     "docs": [] 
    }, 
    { 
     "type": "type3", 
     "docs": [ 
      { 
       "language": "DE" 
      }, 
      { 
       "language": "DE" 
      } 
     ] 
    } 
] 

我的陣列最初由下面的代碼段創建的：

NSMutableArray *docsArray; 
[self setDocsArray:[downloadedDocsArray mutableCopy]]; 

我試圖循環陣列和除去不需要的對象。我嘗試循環數組並將想要的對象複製到新數組。我嘗試過使用NSPredicate而不是循環，所有這些都很少成功。

任何人都可以指向正確的方向嗎？

在此先感謝。

Answer 1

你應該迭代這個數組獲取包含數組的字典進行過濾：

NSArray* results; 
NSMutableArray* filteredResults= [NSMutableArray new]; // This will store the filtered items 
// Here you should have already initialised it 
for(NSDictionary* dict in results) 
{ 
    NSMutableDictionary* mutableDict=[dict mutableCopy]; 
    NSArray* docs= dict[@"docs"]; 
    NSPredicate* predicate= [NSPredicate predicateWithFormat: @"language like 'DE'"]; 
    docs= [docs filteredArrayUsingPredicate: predicate]; 
    [mutableDict setObject: docs forKey: @"docs"]; 
    [filteredResults addObject: mutableDict]; 
}