iPhone：如何使用键从 NSMutable 数组中获取值

发布于 2024-12-24 16:58:04 字数 743 浏览 0 评论 0原文

我想知道如何使用键从 NSMutableArray 中获取值。数组是这样构建的：

    qtype = [[NSMutableArray alloc] init];
    while (dicjson = (NSDictionary*)[enumerator nextObject]) {
     question_id = [dicjson objectForKey:@"question_id"];        
     question_text = [dicjson objectForKey:@"question_text"];
     question_type = [dicjson objectForKey:@"question_type"];

     [qtype addObject:[NSDictionary dictionaryWithObject:question_type forKey:question_id]];

}

我将数组填充到表格单元格中：

 -(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
NSString *type = [qtype objectAtIndex:[indexPath row]];

}

但是输出类似于“65 = YN”，这不是我想要的。我只想提取“65”。如果您能给我一些想法，我将不胜感激。

原文

I would like to know how to fetch a value from a NSMutableArray with keys. The array is built like this:

    qtype = [[NSMutableArray alloc] init];
    while (dicjson = (NSDictionary*)[enumerator nextObject]) {
     question_id = [dicjson objectForKey:@"question_id"];        
     question_text = [dicjson objectForKey:@"question_text"];
     question_type = [dicjson objectForKey:@"question_type"];

     [qtype addObject:[NSDictionary dictionaryWithObject:question_type forKey:question_id]];

}

I am populating the array in a table cell:

 -(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
NSString *type = [qtype objectAtIndex:[indexPath row]];

}

however the output is like "65 = YN" which is not what i want. I would like to extract only "65".
If you could give me some idea, would be very much appreciated.

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樱桃奶球 2024-12-31 16:58:05

问题类型的字典似乎只包含一个键，因此您可以实现您想要的，但请记住：字典是使用键的无序集合，而数组是有序使用索引的集合。

无论如何，在 tableView:cellForRowAtIndexPath: 中，修改代码以获取字典中唯一的键（即问题 id）：

-(UITableViewCell *)tableView:(UITableView *)tableView
        cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    NSArray *dictKeys = [[qtype objectAtIndex:[indexPath row]] allKeys];
    NSString *type = [dictKeys objectAtIndex:0];
}

It seems the dictionary for the question type contains only one key, so you can achieve what you want, but remember : dictionaries are unordered collections working with keys, whereas arrays are ordered collections working with indexes.

Anyway, in tableView:cellForRowAtIndexPath:, modify the code to get the only key (which is the question id) in the dictionary :

-(UITableViewCell *)tableView:(UITableView *)tableView
        cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    NSArray *dictKeys = [[qtype objectAtIndex:[indexPath row]] allKeys];
    NSString *type = [dictKeys objectAtIndex:0];
}

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人生百味 2024-12-31 16:58:05

事实上，我真的不明白你为什么使用字典数组。
您可以简单地构建问题文本数组：

qtype = [[NSMutableArray alloc] init];
while (dicjson = (NSDictionary*)[enumerator nextObject]) {
 question_id = [dicjson objectForKey:@"question_id"];        
 question_text = [dicjson objectForKey:@"question_text"];
 question_type = [dicjson objectForKey:@"question_type"];

 [qtype addObject:question_id];

 } 

 -(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
NSString *type = [qtype objectAtIndex:[indexPath row]];

}

但是如果您需要 qtype 用于其他目的，您可以获得

 -(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    NSDictionary *dict = [qtype objectAtIndex:[indexPath row]];
    NSString *type = [[dict allKeys] objectAtIndex:0]; 

}

In the fact, I really don't understand why you use an array of dictionaries.
You can simply build array of question texts:

qtype = [[NSMutableArray alloc] init];
while (dicjson = (NSDictionary*)[enumerator nextObject]) {
 question_id = [dicjson objectForKey:@"question_id"];        
 question_text = [dicjson objectForKey:@"question_text"];
 question_type = [dicjson objectForKey:@"question_type"];

 [qtype addObject:question_id];

 } 

 -(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
NSString *type = [qtype objectAtIndex:[indexPath row]];

}

But if you need qtype for other purposes, you can get

 -(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    NSDictionary *dict = [qtype objectAtIndex:[indexPath row]];
    NSString *type = [[dict allKeys] objectAtIndex:0]; 

}

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请你别敷衍 2024-12-31 16:58:05

这是因为你将 NSDictionary 存储在“qtype”中。尝试：

NSDictionary *dict = [qtype objectAtIndex:[indexPath row]];
NSString *type = [[dict allValues] lastObject];//since you have only one object stored.

It is because you store NSDictionary in "qtype". Try:

NSDictionary *dict = [qtype objectAtIndex:[indexPath row]];
NSString *type = [[dict allValues] lastObject];//since you have only one object stored.

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新一帅帅 2024-12-31 16:58:05

您可以访问 NSDictionary 类型的数组的每个对象。以下是其代码

-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    NSDictionary *dict = [qtype objectAtIndex:[indexPath row]];
    NSString *question_id = [dict objectForKey:@"question_id"];     
    NSString *question_text = [dict objectForKey:@"question_text"];
    NSString *question_type = [dict objectForKey:@"question_type"];
}

you can access each object of array which is of NSDictionary type.Following is the code for that

-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    NSDictionary *dict = [qtype objectAtIndex:[indexPath row]];
    NSString *question_id = [dict objectForKey:@"question_id"];     
    NSString *question_text = [dict objectForKey:@"question_text"];
    NSString *question_type = [dict objectForKey:@"question_type"];
}

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