Iphone 使用for循环搜索数组中的键

我已经创建了一个dictionary，并在dictionary和dictionary数组中设置名称key-value数据，使用for循环迭代数据。但我想搜索名为vinod的密钥名。下面是我的代码

    NSDictionary *dic2 =[[NSDictionary alloc] init];        
    NSDictionary *dic1 =[[NSDictionary alloc] init];
    [dic1 setValue:@"Vinod" forKey:@"fname"];
    [dic2 setValue:@"vishw" forKey:@"lname"];


    [dic2 setValue:@"Tazeen" forKey:@"fname"];  

    [dic2 setValue:@"momin" forKey:@"lname"];


    NSMutableArray *arr =[[NSMutableArray alloc] initWithObjects:dic1,dic2, nil];

    NSLog(@"inside the view did load");


    NSMutableArray *arr2=[[NSMutableArray alloc] init];

    for (int i=0; i<[arr count]; i++)
    {
        NSString *str =[arr objectAtIndex:i];

        NSLog(@"inside the loop");

        [arr2 addObject:str];

     //   NSArray *arr =[[NSArray alloc] initWithObjects:str, nil];
        if ([arr2 containsObject:@"vinod"])
        {
            NSLog(@"first name found in the array");
        }
    }

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提前谢谢

好的。。。也许应该进行彻底的重写。您的代码既复杂，又在某些地方完全错误，我在下面已经指出了这一点

NSMutableDictionary *dic1 =[[NSMutableDictionary alloc] init]; //Your dictionary needs to 
//be mutable, otherwise it will throw exceptions.  
//NSDictionary is immutable.
NSMutableDictionary *dic2 =[[NSMutableDictionary alloc] init];
[dic1 setValue:@"Vinod" forKey:@"fname"];
[dic1 setValue:@"vishw" forKey:@"lname"];


[dic2 setValue:@"Tazeen" forKey:@"fname"];
[dic2 setValue:@"momin" forKey:@"lname"];

//Add all the values from the dictionaries into one master array.
NSMutableArray *arr =[[NSMutableArray alloc] init];
[arr addObjectsFromArray:[dic1 allValues]];
[arr addObjectsFromArray:[dic2 allValues]];

NSLog(@"inside the view did load");

//load those values into a set for faster lookup
NSSet *set = [[NSSet alloc]initWithArray:arr];

//For-in the values.  Fast enumeration is a lot better at this than c-loops
for (NSString *value in arr) {
    if ([set containsObject:@"Vinod"]) {
        NSLog(@"first name found in the array");
    }
}

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我希望这将对您有所帮助，这个示例代码使用with block

NSDictionary *dic2 =[[NSDictionary alloc] init];
NSDictionary *dic1 =[[NSDictionary alloc] init];
[dic1 setValue:@"Vinod" forKey:@"fname"];
[dic2 setValue:@"vishw" forKey:@"lname"];


[dic2 setValue:@"Tazeen" forKey:@"fname"];

[dic2 setValue:@"momin" forKey:@"lname"];


NSMutableArray *arr =[[NSMutableArray alloc] initWithObjects:dic1,dic2, nil];

NSLog(@"inside the view did load");

[arr enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {

    if ([[obj valueForKey:@"fname"] isEqual:@"Vinod"]) {

        NSLog(@"Found it!");

        *stop = YES;

    }

}];

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您的代码包含一些愚蠢的错误，比如向不可变字典添加值

我已更正并找到代码：

NSMutableDictionary *dic2 =[[NSMutableDictionary alloc] init];
NSMutableDictionary *dic1 =[[NSMutableDictionary alloc] init];
[dic1 setValue:@"Vinod" forKey:@"fname"];
[dic2 setValue:@"vishw" forKey:@"lname"];


[dic2 setValue:@"Tazeen" forKey:@"fname"];

[dic2 setValue:@"momin" forKey:@"lname"];


NSMutableArray *arr =[[NSMutableArray alloc] initWithObjects:dic1,dic2, nil];

for (NSDictionary *dictObj in arr) {
    if ([[dictObj valueForKey:@"fname"]isEqualToString:@"Vinod"]) {
        NSLog(@"name found");
    }
}

试试这个：-

    NSPredicate *predicate = [NSPredicate predicateWithFormat:@"fname = %@",@"Vinod];
    NSMutableArray *aMutArray = [NSMutableArray arrayWithArray:aYourArray];
    [aMutArray filterUsingPredicate:predicate];
    NSMutableDictionary *aDictTemp = [aMutArray objectAtIndex:0];

通常，NSPredicate用于过滤出数组或在数组内部搜索。有关更多信息，请查看此链接：-

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您如何在不可变字典中添加对象？它是不可变的，不是吗？您不能向NSDictionary中添加值：D，再次检查第3行和第4行中的错误。您接受的上述答案与此相同，但您不必遍历每个对象。请参考链接。