如何将字符串对象添加到NSMutableArray

Question

我有一个名为randomSelection的NSMutableArray:

NSMutableArray *randomSelection;

然后,如果满足某些条件,我会尝试向此数组添加字符串:

[randomSelection addObject:@"string1"];

然后我尝试输出字符串,以确定它是否已添加它:

NSString *test = [randomSelection objectAtIndex:0];
NSLog(test);

但是没有输出到错误日志,我无法弄清楚原因.

任何帮助/提示赞赏.

Answer 1

我认为你缺少为数组分配内存.所以试试吧

NSMutableArray *randomSelection = [[NSMutableArray alloc] init];
[randomSelection addObject:@"string1"];
NSString *test = [randomSelection objectAtIndex:0];
NSLog(test);

Answer 2

NSMutableArray *randomSelection =  [[NSMutableArray alloc]init];
[randomSelection addObject:@"string1"];

你需要先分配它.