Problem realeasing allocated objects

Question

Crash occurs at [searchDict release]. If I switch order of the two latest lines it still crash on the latest line (now [searchArray release]). I'm quite new to Objective C and I guess I haven't got the alloc/release right... Help? :)

NSMutableDictionary *searchDict = [[NSMutableDictionary alloc] init];
NSMutableArray *searchArray = [[NSMutableArray alloc] init];

for(int i = 0; i < 2; i++) { // Run two times ("Favorites" and "All")
    searchDict = [listOfItems objectAtIndex:i];
    searchArray = [searchDict objectForKey:@"Entries"];

    for (NSString *sTemp in searchArray) {
        NSRange titleResultsRange = [sTemp rangeOfString:searchText options:NSCaseInsensitiveSearch];
        if (titleResultsRange.length > 0)
            [listOfItemsDynamic addObject:sTemp];
    }
}

[searchArray release];
[searchDict release];

Answer 1

You allocate space and assign it to the variables:

NSMutableDictionary *searchDict = [[NSMutableDictionary alloc] init];
NSMutableArray *searchArray = [[NSMutableArray alloc] init];

But then you assign non locally-allocated data to them:

searchDict = [listOfItems objectAtIndex:i];
searchArray = [searchDict objectForKey:@"Entries"];

So basically, you don't need to allocate and release. Instead do something like this:

NSMutableDictionary *searchDict; // Just declartion, no allocation / init
NSMutableArray *searchArray;     // Just declartion, no allocation / init

for(int i = 0; i < 2; i++) { // Run two times ("Favorites" and "All")
    searchDict = [listOfItems objectAtIndex:i];
    searchArray = [searchDict objectForKey:@"Entries"];

    for (NSString *sTemp in searchArray) {
        NSRange titleResultsRange = [sTemp rangeOfString:searchText options:NSCaseInsensitiveSearch];
        if (titleResultsRange.length > 0)
            [listOfItemsDynamic addObject:sTemp];
    }
}

// No release needed here

If you are familiar with C, it is similar to:

char *pChar;
pChar = malloc(15); // allocate memory and assign to pChar
pChar = "Hello";    // assign new address to pChar
free(pChar); // Error here ;)