rewriting dates

pereirap · June 2012

Im having some trouble changing the dates in an array of dictionary objects. The basic code is below.

The contents of arrayOfNewsItems checks out fine I use this loop to check beforehand:

// check items before
	for (int t=0; t<[arrayOfNewsItems count]; t++){
		NSLog(@\"Items before: %@\",[[arrayOfNewsItems objectAtIndex:t] objectForKey:@\"pubDate\"]);
	}

Then I make some changes to the date field removing some unwanted letters:

// Now loop through and check for weird characters in the date, and remove them
	NSMutableDictionary *tempDict = [[NSMutableDictionary alloc] init];
	NSString *currentDate = [[NSString alloc] init];
	
	for (int i=0; i<[arrayOfNewsItems count]; i++){
		NSLog(@\"Date before: %@\",[[arrayOfNewsItems objectAtIndex:i] objectForKey:@\"pubDate\"]);
		[tempDict setDictionary:[arrayOfNewsItems objectAtIndex:i]];		
		currentDate = [tempDict objectForKey:@\"pubDate\"];
		currentDate = [currentDate stringByReplacingOccurrencesOfString:@\"T\" withString:@\" \"];
		currentDate = [currentDate stringByReplacingOccurrencesOfString:@\" ue\" withString:@\"Tue\"];
		currentDate = [currentDate stringByReplacingOccurrencesOfString:@\" hu\" withString:@\"Thu\"];
		currentDate = [currentDate stringByReplacingOccurrencesOfString:@\"GM \" withString:@\"GMT\"];
		currentDate = [currentDate stringByReplacingOccurrencesOfString:@\"ED \" withString:@\"EDT\"];
		currentDate = [currentDate stringByReplacingOccurrencesOfString:@\"Z\" withString:@\" \"];
		[tempDict removeObjectForKey:@\"pubDate\"];
		[tempDict setValue:currentDate forKey:@\"pubDate\"];		
		[arrayOfNewsItems replaceObjectAtIndex:i withObject:tempDict];
		NSLog(@\"Date after: %@\",[[arrayOfNewsItems objectAtIndex:i] objectForKey:@\"pubDate\"]);
	}// end for

According to my debug statements within the loop, my changes are working for that section also. But, when I check the values afterwards (using the loop below), the dates are all the same.

// check items after
	for (int r=0; r<[arrayOfNewsItems count]; r++){
		NSLog(@\"Items after: r= %i %@\",r,[[arrayOfNewsItems objectAtIndex:r] objectForKey:@\"pubDate\"]);
	}

What am I missing, or misusing?

Fstuff · June 2012

You're abusing NSMutableDictionary for one. Or at least, it's not doing what you think it's doing. As best I can tell, you are trying in your for-loop to iterate through an array of dictionaries, and replace each dictionary with an updated copy of each entry. It seems that you are trying to accomplish this by calling [NSMutableDictionary setDictionary]. However, you are still dealing with the same NSMutableDictionary object on each iteration. The value of 'tempDict' is set by this line:

NSMutableDictionary *tempDict = [[NSMutableDictionary alloc] init];

But you never create any other NSMutableDictionary objects nor do you pull any NSMutableDictionary objects out of your array. Therefore you are pointing each index of your array to the same NSMutableDictionary object.

I'm also not sure what you are trying to accomplish with the dates but it seems unwieldy. Check out Apple's Time and Date programming guide, it might help you find a better way to accomplish your goal.

Finally, a suggestion: Use the Code tag to format your code. Preserves spacing/indentation and is typically easier to read.

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