NSMutableArray，添加/删除对象？

Question

Is this the correct way to pop objects off the front of an array. I was just curious as I was thinking there might be a method for NSMutableArray that returned a retained object. Just curious if I am getting this right?

// PUTTING OBJECTS IN
NSMutableArray *fgStore = [[NSMutableArray alloc] init];
for(int counter=1; counter<=5; counter++) {
    NSString *dataValue = [[NSString alloc] initWithFormat:@"DATA%d", counter];
    [fgStore addObject:dataValue];
    [dataValue release];
}

// TAKING OBJECTS OUT
NSString *saveMe = [[fgStore objectAtIndex:0] retain];
[fgStore removeObjectAtIndex:0];    
NSLog(@"SAVE: %@", saveMe);
...
...
[fgStore release];
[saveMe release];

gary

Answer 1

This is exactly the way I would do it, I don't think there's another. By returning a retained object you would break one of the main rules of Cocoa memory management: Most of the time you only own the objects returned by init… methods and have to retain the rest.

Answer 2

That code looks fine. The only thing you might want to keep in mind is that you can use autorelease to avoid the explicit releases when you're done. For instance:

for(int counter=1; counter<=5; counter++) {
    NSString *dataValue = [[[NSString alloc]
                             initWithFormat:@"DATA%d", counter] autorelease];
    [fgStore addObject:dataValue];
}

I don't believe there is any NSMutableArray method that returns a retained object. Remember that methods which return retained values have names which start with alloc, new, or copy.