空NSMutableArray，不知道为什么 [英] Empty NSMutableArray , not sure why

问题描述

好的，所以我填充这样的数组：

Ok so I populate the array like this:

NSMutableArray *participants;
for(int i = 0; i < sizeofpm; i++){
        NSDictionary *pmpart_dict = [pm_participants objectAtIndex:i];
        NSString *pmpart_email = [pmpart_dict objectForKey:@"email"];
        NSString *pmpart_email_extra = [@"pm" stringByAppendingString:pmpart_email];
        [participants setValue:pmpart_email forKey:pmpart_email_extra];
        NSLog(@"%@", participants);
    } 

sizeofpm是1.正在使用count。获取数组中的值的数量。如何将值存储到该数组？它似乎没有工作。谢谢！

sizeofpm is 1. that is using count. to get the number of values in the array. How can i store values to that array? It doesnt seem to be working. Thanks!

推荐答案

您需要先分配它。尝试将第一行更改为：

you need to alloc it first. Try to change the first line to:

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

还使用 setValue：forKey：不能使用 NSMutableArray 因为数组没有键。

also using setValue:forKey: wont work with an NSMutableArray as an array has no key.

尝试使用 [参与者addObject：pmpart_email]; 。

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