emoji comparison error with NSUserDefaults - ios

Question

I created a emoji menu where users can choose them and use on top of pictures. However, it has been quite hard to get the "recently chosen emoji" part working properly because NSUserDefaults probably. When I choose an emoji in any of the 8 views, this emoji is added to an NSMutableArray, and the next time I open the emoji menu, this emoji is the first to appear in the "recently chosen emoji" view, as expected. I implemented the following code so that when I choose an emoji (be it directly through the "recently chosen emoji view" or just through any of the 8 other views - the 9 views are connected through a horizontal scroll view - if this emoji is already present at the "recently chosen emoji view", it is deleted from the view and added to the beginning of the view). Actually, I delete from the index in the emoji array, remove all subviews from the "recently chosen emoji" view and repopulate it with subviews according to the new emoji array:
- (void)emojiButtonPressed:(UIButton *)button {
NSLog(#"ARRAY EQUALS = %#", historicEmojiQueue);
NSLog(#"ARRAY AMOUNT EQUALS = %lu", (unsigned long)[historicEmojiQueue count]);
if ([historicEmojiQueue count] < 30){
NSLog(#"Not full");
for ( int j = 0; j < [historicEmojiQueue count]; j++){
NSLog(#"IN THE LOOP - START PRINT");
NSLog(#"%#", button.titleLabel.text);
NSLog(#"%#", historicEmojiQueue[j]);
NSLog(#"IN THE LOOP - END PRINT");
if ( button.titleLabel.text == historicEmojiQueue[j] ){
NSLog(#"EQUAL ADDITION TO ITEM ALREADY PRESENT");
[historicEmojiQueue removeObjectAtIndex:j];
}
}
[historicEmojiQueue insertObject:button.titleLabel.text atIndex:0];
}
else{
NSLog(#"Full");
BOOL equal = NO;
for ( int j = 0; j < [historicEmojiQueue count]; j++){
NSLog(#"IN THE LOOP - START PRINT");
NSLog(#"%#", button.titleLabel.text);
NSLog(#"%#", historicEmojiQueue[j]);
NSLog(#"IN THE LOOP - END PRINT");
if ( button.titleLabel.text == historicEmojiQueue[j] ){
NSLog(#"EQUAL ADDITION TO ITEM ALREADY PRESENT");
[historicEmojiQueue removeObjectAtIndex:j];
equal = YES;
}
}
if (equal == NO){
[historicEmojiQueue removeLastObject];
}
[historicEmojiQueue insertObject:button.titleLabel.text atIndex:0];
}
NSLog(#"ARRAY EQUALS aF= %#", historicEmojiQueue);
NSLog(#"ARRAY AMOUNT EQUALS aF= %lu", (unsigned long)[historicEmojiQueue count]);
[[NSUserDefaults standardUserDefaults] setObject:historicEmojiQueue forKey:#"historicQueue"];
[[NSUserDefaults standardUserDefaults] synchronize];
(MORE CODE THAT DOES NOT AFFECT THE PROBLEM)
}
When I choose an emoji, lets say Pizza, then choose another 5 emoji that are different, and choose Pizza again, it works perfectly: Pizza is removed from the sixth position and added to the first.
If I run the app again, my last changes are saved to NSUserDefaults, so Pizza will be the first emoji to display on the "recently chosen emoji" view. Now, if I choose Pizza again, the old Pizza and first on the list is not removed, and the new one is added, then having two Pizza emoji on the first and second position of the array, and then, in the view.
If I tap on any of the old emojis in the view ( like the second pizza), it is removed and added to the beginning. In the case of the Pizza, tapping on the old Pizza (second position) will not produce any visible changes since they are equal, but I am sure they exchange places. Here is the code in ViewDidLoad to get the array from NSUserDefaults:
NSMutableArray * historicEmojiQueue;
#implementation myEmojiView
-(instancetype)initWithFrame:(CGRect)frame{
self = [super initWithFrame:frame];
if (self) {
NSMutableArray * permanentQueue = [[NSUserDefaults standardUserDefaults] objectForKey: #"historicQueue"];
if ( permanentQueue == NULL) {
historicEmojiQueue = [[NSMutableArray alloc] init];
[[NSUserDefaults standardUserDefaults] setObject:historicEmojiQueue forKey:#"historicQueue"];
}
else{
historicEmojiQueue = [[NSMutableArray alloc] initWithArray:permanentQueue copyItems:YES];
}
}
(MORE CODE)
}
The reason of my question is the result of the print of the first block of code:
ARRAY EQUALS = (
"\Ud83c\Udf55",
"\Ud83c\Udf4e",
"\Ud83c\Udf4e",
"\Ud83c\Udf4e",
"\Ud83c\Udf52",
"\Ud83d\Ude18",
"\Ud83d\Ude43",
"\Ud83c\Udfc8",
"\Ud83c\Udf4e",
"\Ud83c\Udf4e",
"\Ud83d\Ude44",
"\Ud83d\Ude0e",
"\Ud83e\Udd14",
"\Ud83d\Ude12",
"\Ud83d\Ude07",
"\Ud83d\Ude1c",
"\Ud83e\Udd11",
"\Ud83d\Ude17",
"\Ud83d\Ude18",
"\Ud83c\Udf55",
"\Ud83c\Udf2d",
"\Ud83c\Udf56",
"\Ud83c\Udf4f",
"\Ud83c\Udf50",
"\Ud83c\Udf4b",
"\Ud83c\Udf4a",
"\Ud83d\Udc2f",
"\Ud83c\Udf46",
"\Ud83d\Udc3d",
"\Ud83d\Ude4a"
)
ARRAY AMOUNT EQUALS = 30
Full
IN THE LOOP - START PRINT
🍕
🍕
IN THE LOOP - END PRINT
IN THE LOOP - START PRINT
🍕
🍎
IN THE LOOP - END PRINT
.... ( LOTS OF OTHER PRINT STATEMENTS INSIDE LOOP)
ARRAY EQUALS aF= (
"\Ud83c\Udf55",
"\Ud83c\Udf55",
"\Ud83c\Udf4e",
"\Ud83c\Udf4e",
"\Ud83c\Udf4e",
"\Ud83c\Udf52",
"\Ud83d\Ude18",
"\Ud83d\Ude43",
"\Ud83c\Udfc8",
"\Ud83c\Udf4e",
"\Ud83c\Udf4e",
"\Ud83d\Ude44",
"\Ud83d\Ude0e",
"\Ud83e\Udd14",
"\Ud83d\Ude12",
"\Ud83d\Ude07",
"\Ud83d\Ude1c",
"\Ud83e\Udd11",
"\Ud83d\Ude17",
"\Ud83d\Ude18",
"\Ud83c\Udf55",
"\Ud83c\Udf2d",
"\Ud83c\Udf56",
"\Ud83c\Udf4f",
"\Ud83c\Udf50",
"\Ud83c\Udf4b",
"\Ud83c\Udf4a",
"\Ud83d\Udc2f",
"\Ud83c\Udf46",
"\Ud83d\Udc3d"
)
ARRAY AMOUNT EQUALS aF= 30
As you can see, even though the first emoji is exactly equal to the second both printed and in their unicode strings, they do not pass the check of whether they are equal as if they had different string representations. Since when I do not run the application again from Xcode and choose two equal emojis they do pass the check and print "EQUAL ADDITION TO ITEM ALREADY PRESENT", I am sure the problem relates to data being retrieved from NSUserDefaults, even though when I print the array I got from NSUserDefaults, it is exactly the same. I've tried multiple things when copying array from NSUserDefaults like [[NSMutableArray alloc] initWithArray:permanentQueue copyItems:YES]; and even looping through the NSUserDefaults array copying each item but nothing seems to solve the problem. Please help! :(

Answer 1

Where you are comparing strings at
if ( button.titleLabel.text == historicEmojiQueue[j] )
you should be using
if ( [button.titleLabel.text isEqualToString:historicEmojiQueue[j]] )
The first compares whether they occupy the same memory, the second whether they match.