如何编辑NSMutableArray数据？

Question

我有这样的NSMutableArray

sections = [[NSMutableArray alloc] init]; 
[sections addObject:[[NSMutableDictionary alloc] initWithObjectsAndKeys:@"Electricity",@"Type",@"0",@"Count", nil]]; 
    [sections addObject:[[NSMutableDictionary alloc] initWithObjectsAndKeys:@"Water",@"Type",@"0",@"Count", nil]]; 
    [sections addObject:[[NSMutableDictionary alloc] initWithObjectsAndKeys:@"Mobile",@"Type",@"0",@"Count", nil]]; 
    [sections addObject:[[NSMutableDictionary alloc] initWithObjectsAndKeys:@"Internet",@"Type",@"0",@"Count", nil]]; 
    [sections addObject:[[NSMutableDictionary alloc] initWithObjectsAndKeys:@"Fixed Line",@"Type",@"0",@"Count", nil]]; 

，并让说，用户选择从0更改为水数为10怎么办？

Answer 1

[[sections objectAtIndex:1] setObject:@"10" forKey:@"Count"];

一件事。当你用alloc + init创建对象时，你应该自己释放它们。因此，对于每个NSMutableDictionary，您都有内存泄漏（在您的代码中）。
使用[[[NSMutableDictionary alloc] initWithObjectsAndKeys:..., nil] autorelease];或[NSMutableDictionary dictionaryWithObjectsAndKeys:..., nil];（当然，以后可以制作类似for (NSMutableDictionary *dict in sections) [dict release];的东西，但这看起来很难看）。