Exercise 15-3 (is this the proper way to go about avoiding a memory leak?)

[mdziedzic]

From AddressBook.h:

Code: (Objective-C)

-(NSMutableArray *) lookup: (NSString *) theName
{
	NSMutableArray *matches = [[NSMutableArray alloc] init];
	
	for (AddressCard *nextCard in book) {
		NSRange textSearch = [[nextCard name] rangeOfString: theName options: NSCaseInsensitiveSearch];
		if (textSearch.location != NSNotFound)
			[matches addObject: nextCard];
	}
	
	[matches autorelease];
	return matches;
}

Code: (Objective-C)

#import <Foundation/Foundation.h>
#import "AddressBook.h"


int main (int argc, const char * argv[]) {
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
	
	NSString *aName = @"Julia Kochan";
	NSString *aEmail = @"jewls377@axlc.com";
	NSString *bName = @"Tony Iannino";
	NSString *bEmail = @"tony.iannino@techfitness.com";
	NSString *cName = @"Stephen Kochan";
	NSString *cEmail = @"steven@kochan.wood.com";
	NSString *dName = @"Jamie Baker";
	NSString *dEmail = @"jbaker@kochan-wood.com";
	NSString *eName = @"Maki Dziedzic";
	NSString *eEmail = @"maki@eggfoo.com";

	
	AddressCard *card1 = [[AddressCard alloc] init];
	AddressCard *card2 = [[AddressCard alloc] init];
	AddressCard *card3 = [[AddressCard alloc] init];
	AddressCard *card4 = [[AddressCard alloc] init];
	AddressCard *card5 = [[AddressCard alloc] init];

	
	AddressBook *myBook = [AddressBook alloc];
	NSMutableArray *matchedCards;
	
	// first set up four address cards
	
	[card1 setName: aName andEmail: aEmail];
	[card2 setName: bName andEmail: bEmail];
	[card3 setName: cName andEmail: cEmail];
	[card4 setName: dName andEmail: dEmail];
	[card5 setName: eName andEmail: eEmail];

	
	myBook = [myBook initWithName: @"Michael's Address Book"];
	
	// add some cards to the address book
	
	[myBook addCard: card1];
	[myBook addCard: card2];
	[myBook addCard: card3];
	[myBook addCard: card4];
	[myBook addCard: card5];
	
	// look up a person by name
	
	NSString *searchTerm = @"ko";
	
	NSLog(@"Lookup: %@", searchTerm);
	matchedCards = [myBook lookup: searchTerm];
	
	if (matchedCards != nil) {
		for (AddressCard *theCard in matchedCards)
			[theCard print];
	} else {	
		NSLog(@"Not found!");
	}
	
	[card1 release];
	[card2 release];
	[card3 release];
	[card4 release];
	[card5 release];
	[myBook release];
	
	[pool drain];
    return 0;
}

[mdziedzic]

Or better...

Code: (Objective-C)

-(NSMutableArray *) lookup: (NSString *) theName
{
	NSMutableArray *matches = [[[NSMutableArray alloc] init] autorelease];
	
	for (AddressCard *nextCard in book) {
		NSRange textSearch = [[nextCard name] rangeOfString: theName options: NSCaseInsensitiveSearch];
		if (textSearch.location != NSNotFound)
			[matches addObject: nextCard];
	}
	
	return matches;
}

[skochan]

Yep, they're both fine!

Cheers,

Steve Kochan

[kadegray]

Im doing this exercise now. So im yet to do chapter 17 on Memory Managment.

If you just used autorelease, then you used that method a whole bunch of times, objects will keep being made and added to the autorelease pool, hence wasting memory while the program is running. Is this true?

So I'm trying to remember how to release the object the method created after its been returned. I'm sure there was a tidier way of doing it, rather than just going [object release] after your done with the object the method created. Or is that all you do?

[skochan]

If you just used autorelease, then you used that method a whole bunch of times, objects will keep being made and added to the autorelease pool, hence wasting memory while the program is running. Is this true?

Yes, that's true

So I'm trying to remember how to release the object the method created after its been returned. I'm sure there was a tidier way of doing it, rather than just going [object release] after your done with the object the method created. Or is that all you do?

Yeah, there's no other trick for handling that.

Cheers,

Steve