I am trying to populate the Title, and Subtitle using mapkit with the following lines of code.
The textItems array holds two strings.
NSArray *textItems = [searchString componentsSeparatedByString:#","];
addAnnotation =
[[AddressAnnotation alloc] initWithCoordinate:location
mTitle:[[textItems objectAtIndex:0] stringValue]
mSubTitle:[[textItems objectAtIndex:1] stringValue]];
The app stops when it reaches the 'addAnnotation'.
If I change mTitle:[[textItems objectAtIndex:0] stringValue] to mTitle:#"test" i.e. it works fine. When I debug I can see that the data in the textItems array is present.
Any ideas?
Thanks.
The componentsSeparatedByString method returns an array of NSString objects.
You are calling stringValue on those objects but stringValue applies to NSNumber objects--not NSString so you must be getting an "unrecognized selector" error.
Remove the calls to stringValue:
addAnnotation = [[AddressAnnotation alloc] initWithCoordinate:location
mTitle:[textItems objectAtIndex:0]
mSubTitle:[textItems objectAtIndex:1]];
However, it would still be a good idea to check the count before accessing those indexes in the array and use a default value if the array returns only 0 or 1 objects.
I would set a breakpoint between the first and second line you posted. When you get there, go down to the console and type "po textItems" and "po [textItems count]". They will print the array and the number of objects in the array respectively. At the very least it's a check to make sure that you're getting the number of objects in the array you expect.
Related
I am using one NSMutableArray with same string object.
Here is the code
NSMutableArray *arr = [[NSMutableArray alloc]initWithObjects:#"hello",#"hi",#"hi",#"hi",#"hi",#"hi",#"hi",#"hi",#"hi",#"hi",#"hi",#"hi",#"hi",nil];
NSObject *obj = [arr objectAtIndex:2];
[arr removeObject:obj];
NSLog(#"%#",arr);
When i try to remove 3rd object of array, its removing all object with "hi" string.
I am not getting why its happening.
my doubt is while removing object, NSMutableArray match string or address.
It's because you're using removeObject which removes all objects that are "equal" to the one you pass in. As per this Apple documentation:
This method uses indexOfObject: to locate matches and then removes
them by using removeObjectAtIndex:. Thus, matches are determined on
the basis of an object’s response to the isEqual: message. If the
array does not contain anObject, the method has no effect (although it
does incur the overhead of searching the contents).
You're seeing the effects of literal strings here where each of those #"hi" objects will turn out to be the same object just added many times.
What you really want to do is this:
NSMutableArray *arr = [[NSMutableArray alloc]initWithObjects:#"hello",#"hi",#"hi",#"hi",#"hi",#"hi",#"hi",#"hi",#"hi",#"hi",#"hi",#"hi",#"hi",nil];
[arr removeObjectAtIndex:2];
NSLog(#"%#",arr);
Then you're specifically removing the object at index 2.
According to https://developer.apple.com/library/mac/#documentation/Cocoa/Reference/Foundation/Classes/NSMutableArray_Class/Reference/Reference.html
removeObject:
Removes all occurrences in the array of a given object.
which is exactly the behaviour you're seeing. If you want to remove the object at a particular position, you want removeObjectAtIndex:.
NSMutableArray *arr = [[NSMutableArray alloc]initWithObjects:#"hello",#"hi",#"hi",#"hi",#"hi",#"hi",#"hi",#"hi",#"hi",#"hi",#"hi",#"hi",#"hi",nil];
NSUInteger obj = [arr indexOfObject:#"hi"]; //Returns the lowest integer of the specified object
[arr removeObjectAtIndex:obj]; //removes the object from the array
NSLog(#"%#",arr);
How would I filter through an array and return values that contain a certain part of a string? I have a text box where, for the sake of this example, a user puts in 25, and then hits a "Done" button.
Example:
Original Array {25-1002, 25-1005, 12-1003, 1000-0942, 1-1, 234-25}
I want it to return (after sorting through it and pulling the values I want):
New Array {25-1002, 25-1005}
Please note that in the original array, the last value of 234-25 has a 25 in it as well but is not pulled through. It needs to be the number on the first part of the hyphen.
Thanks in advance!
Use the -filteredArrayUsingPredicate: method, like this:
NSString *searchText = [someField.text stringByAppendingString:#"-"];
newArray = [originalArray filteredArrayUsingPredicate:[NSPredicate predicateWithBlock:^(NSString *value, NSDictionary *bindings){
return ([value rangeOfString:searchText].location != NSNotFound)
}]];
Note that blocks (the ^{} thing) aren’t available pre-iOS 4, so you’ll have to use another of NSPredicate’s constructors if you’re targeting 3.x devices as well.
as an easy to understand answer (not using NSPredicate, which can be intimidating (but is really the correct way to do it)):
NSMutableArray *myNewArray = [[NSMutableArray alloc] init];
for (NSString *string in myArray) {
if([[string substringToIndex:3] isEqualToString #"25-"])
{
[myNewArray addObject:string];
}
}
i wanted to know how to add strings into an array.
I used the following methods but it is showing null.
1) [arrData addObject:[NSString stringWithString:strlast]];
2) [arrData addObject:strlast];
Thanks in advance
You can't add anything to an NSArray once it's created. You need to use an NSMutableArray if you want to make changes to it.
Update: You may actually have two problems.
Using an NSArray instead of an NSMutableArray when mutability is needed.
Not initializing the array object (either kind). If arrData is nil, you can happily send as many messages as you want to nil. Nothing will happen.
If it is showing null (nil) you need to make sure you set arrData somewhere in your code before trying to addObject:.
arrData = [[NSMutableArray alloc] init];
Also strlast is a string so use your second example, the first example is pointless.
[arrData addObject:strlast];
Did you allocate an array and assign it to arrData?
Try:
NSMutableArray *arrData = [NSMutableArray array];
NSString *string = #"My string";
[arrData addObject:string];
NSLog(#"%#", [arrData objectAtIndex:0]); //logs "My string"
If you're using a non-mutable array, you can also use arrayByAddingObject:
arrData = [arrData arrayByAddingObject: strlast];
but a mutable array is probably a better idea.
In my iphone app i have implemented the SearchBar on TableView.
Now the SearchBar Searches the items but the searched items are not shown in the tableview as the NSMutableArray which fills up the table with the search results is not retaining the values.
I have put the screenshot of the code and the NSLog statements for the count of copyListOfItems always return 0 even though the NSLog(#"%#",sTemp); shows the searched items in Console.
I have created the property for the NSMutableArray copyListOfItems and also synthesized it but its count in the Console is always shown as Zero.
Here is the Code:
searchArray = [Food mutableCopy];
for (NSString *sTemp in searchArray)
{
NSLog(#"Value: %#",NSStringFromClass([sTemp class]));
NSRange titleResultsRange = [sTemp rangeOfString:searchText options:NSCaseInsensitiveSearch];
if (titleResultsRange.length > 0)
{
NSLog(#"sTemp is:%#",sTemp);
NSLog(#" is:%#",sTemp);
[copyListOfItems addObject:sTemp];
[copyListOfItems retain];
}
NSLog(#"Copy list count in Search Delegate Method inside For : %d",[copyListOfItems count]);
}
NSLog(#"Copy list count in Search Delegate Method : %d",[copyListOfItems count]);
[searchArray release];
searchArray = nil;
searching = YES;
[self.table reloadData];
de:
What should I do?
Please Help
Please Suggest
Thanks
From what you've said, it sounds as though the copyListOfItems array is never created. Synthesizing the property creates a pair of accessor methods, but doesn't automatically create an instance of NSMutableArray for you.
So somewhere, you'll need to call [[NSMutableArray alloc] init] (or some variant of init...), and assign the result to the instance variable, or call [NSMutableArray array] (or a variant of array...), and pass the result as an argument to the setCopyListOfItems: method.
I can only assume that you're over-releasing the items in the array. It appears that you do not have a good grip on the retain/release concept, since you're over-retaining the NSArray copyListOfItems. You shouldn't be calling -retain on the same object within a loop since you're incrementing a single object's retain count by 1 for each iteration of the loop.
That aside, what does this code output in its NSLog() calls? It doesn't make a lot of sense. Why do you try to take a mutable copy of (what appears to be) a class called Food?
What exactly is "Food"? An objective-C object, or an objective-C class? This should not be compiling at all in my opinion, unless it's just very badly named.
Make sure you always alloc init the NSMutableArray. If you don't do that, all the items you add will just euhm.. disappear. So make sure you do this somewhere:
searchArray = [[NSMutableArray alloc] init];
Oops..!!!! Cleaned my project and build and run again and it has started working.Thanks guys for being so helpful.. :]
where are you creating the copyListOfItems Array?
I guess copyListOfItems is nil. And you are trying to add something to nil array and trying to retain the nil.
Note: whatever the operation you do on the nil will not be affected. Check whether you are creating the copyListOfItems array properly.
And why are you trying to retain the same array after adding each object?
See this code:
int i = years;
NSLog(#"Years i: %i",i);
NSString *syears= [NSString stringWithFormat:#"%d",i];
menuList = [[NSMutableArray alloc] init];
[menuList addObject:[NSMutableDictionary
dictionaryWithObjectsAndKeys:
#"years", kLeftKey,
syears, kRightKey, nil, kControllerKey, nil]];
The above is an extract from ViewWillAppear. When I switch between tabs ViewWillAppear is doing it's job and the data is updating down as far as NSString *syears= [NSString stringWithFormat:#"%d",i]; but after that my array doesn't get updated with the latest value of syears. I tried using setObject and setValue but these don't work with NSMutableArray. Any ideas?
Keys and values in NSDictionary need to be non-nil NSObjects. So you've definitely got an issue with a nil in there, and there may be a question about kLeftKey et al, for which you haven't shown the definitions.
More generally, it would help to know what you are doing with menuList and what you mean by "my array doesn't get updated". Are you trying to display it? Using it as a data source somewhere? You are creating the array anew here -- could a previous reference be being left around and displayed?