Iterar遍歷實體數組，並根據「其他關鍵字」matche的值獲取某個鍵的值

我有一個實體類的數組（例如SubmittedAnswer）。其JSON格式如下所示。Iterar遍歷實體數組，並根據「其他關鍵字」matche的值獲取某個鍵的值

{ 
"submittedAnswers": [{ 
    "submittedQuestionId": "C7B3C4BE-CC3C-438F-A118-E798884A5FE0", 
    "serialNumber": 4, 
    "option": " it has a very large mass.", 
    "testQuestionId": "55230160-b905-47d5-a91c-e1dda6dd0634", 
}, { 
    "submittedQuestionId": "9A6E9EA8-1BC0-4ED9-81E8-28B7E554D5E0", 
    "serialNumber": 1, 
    "option": " downward", 
    "testQuestionId": "fd0b3ae0-e999-48a6-89b8-a89b02e7b793", 
}] 

}

我想找到「選項」從數組，其「submittedQuestionId」場「的東西......」。我不想用循環。目前我正在使用以下代碼。

NSString *submittedQuestionId = "something...." 
int index = [[submittedAnswers valueForKey:@"submittedQuestionId"] indexOfObject:submittedQuestionId]; 
NSString *option = [[submittedAnswers valueForKey:@"option"] objectAtIndex:index];

我需要更好的解決方案來解決這個問題。

來源

2012-12-20 milanpanchal

假設submittedAnswers是的NSDictionary對象的一個NSArray，我在這裏找到了答案： Stack Overflow > iPhone - Searching NSArray of NSDictionary objects

// Array `submittedAnswers` of sample data 
NSArray* submittedAnswers = @[ 
@{ 
@"submittedQuestionId" : @"C7B3C4BE-CC3C-438F-A118-E798884A5FE0" , 
@"serialNumber" : @4 , 
@"option" : @" it has a very large mass." , 
@"testQuestionId" : @"55230160-b905-47d5-a91c-e1dda6dd0634" } , 
@{ 
@"submittedQuestionId" : @"9A6E9EA8-1BC0-4ED9-81E8-28B7E554D5E0" , 
@"serialNumber" : @1 , 
@"option" : @" downward" , 
@"testQuestionId" : @"fd0b3ae0-e999-48a6-89b8-a89b02e7b793" } ] ; 


NSString *submittedQuestionId = @"9A6E9EA8-1BC0-4ED9-81E8-28B7E554D5E0" ; 
NSPredicate* predicate = [NSPredicate predicateWithFormat:@"submittedQuestionId = %@", submittedQuestionId] ; 
NSArray* foundQuestions = [submittedAnswers filteredArrayUsingPredicate:predicate] ; 
NSDictionary* foundQuestion = foundQuestions[0] ;

來源

2012-12-20 16:06:20

NSPredicate *predicate = [NSPredicate predicateWithFormat:@"submittedQuestionId == %@", yourSubmittedQuestionId]; 
NSArray *filteredArray = [myArray filteredArrayUsingPredicate:predicate]; 
id firstFoundObject = nil; 
if ([filteredArray count] > 0) { 
    firstFoundObject = [filteredArray objectAtIndex:0]; 
}

請確保您的SubmittedAnswer類具有財產submittedQuestionId

來源

2012-12-20 16:10:56

Iterar遍歷實體數組，並根據「其他關鍵字」matche的值獲取某個鍵的值

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