i have the following line of code
NSMutableArray *marray = [[NSArray arrayWithObjects: #"4", #"1", #"9", nil]mutableCopy];
and i want to replace it with the following line
NSMutableArray *marray = [[NSMutableArray alloc]initWithArray:garr];
where garr is global array from global method
the problem is that the code works fine when calling the first line but when using the second one the code crash , appreciate ur help and ideas thanks , iknow that the first one is NSArray but the garr variable source is NSMutable array
here is the code for garr
garr = [[NSMutableArray alloc]init];
for (int x = 0; x < 10; x++) {
[garr addObject:[NSNumber numberWithInt: arc4random()%200]];
here is the error msg
console error:2012-09-02 14:46:42.976 sort_alg[1561:207] -[NSCFNumber UTF8String]: unrecognized selector sent to instance 0x4b1a170 2012-09-02 14:46:42.978 sort_alg[1561:207] * Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[NSCFNumber UTF8String]: unrecognized selector sent to instance 0x4b1a170' * Call stack at first throw: –
this is the code that generates the end value
NSString *element;
NSEnumerator *iterator = [marray objectEnumerator];
while ((element = [iterator nextObject]) != nil)
printf("%s ", [element UTF8String]);
printf("\n");
[marray release]; // array needs to be released!
[pool release];
thanks
Problem lies in printf("%s ", [element UTF8String]);.
NSNumber has no UTF8String method, only a stringValue. You can't printf it either, but you can NSLog("%#", [element stringValue]), or NSLog("%d", [element intValue]) if you know it's an int.
Related
could you please help me to solve the following error:
Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: '-[__NSCFArray replaceObjectAtIndex:withObject:]: mutating method sent to immutable object'
array_Info = [[NSMutableArray alloc] init];
array_Info = [dict_Temp objectForKey:#"Children"];
NSMutableArray *temp = [[NSMutableArray alloc] initWithArray:self.array_Info];
int ran, arrayIndexing = 0;
while ([temp count] != 0)
{
ran = arc4random();
if(ran < 0)
ran*=-1;
ran = ran % [temp count];
if([temp count] == 1)
ran = 0;
NSLog(#"%d %d",arrayIndexing,ran);
[self.array_Info replaceObjectAtIndex:arrayIndexing withObject:[temp objectAtIndex:ran]];
[temp removeObjectAtIndex:ran];
arrayIndexing++;
}
Presuming that array_Info is the backing variable for the self.array_Info property, you should change your second line to:
array_Info = [[dict_Temp objectForKey:#"Children"] mutableCopy];
This will give you the mutable array you need for the replaceObjectAtIndex:withObject: call.
It seems that self.array_Info is an immutable array. Make it mutable.
I'm new to objective-c and I decided to start by working through Stanford's CS193s 2010F Session's lectures/assignments.
I was working on the second assignment, and I was stuck when I had to return a NSString that combines(concatenates) every strings inside NSMutableArray. (The MutableArray consists only NSString at its each indices)
My approach was to use a for loop to pass through the MutableArray's indicies(in the code below, the MutableArray is 'anExpression' with type 'id'). I declared a NSMutableString and added NSString at each indices of 'anExpression' array. Here is the code:
+ (NSString *)descriptionOfExpression:(id)anExpression{
NSMutableString *result = [NSMutableString string];
for (int i = 0;i<[anExpression count];i++){
[result appendString:[anExpression objectAtIndex:i]];
}
return result;
}
However, at
[result appendString:[anExpression objectAtIndex:i]];
xcode crashes with following error statements:
2012-07-17 01:44:51.014 Calculator[9470:f803] -[__NSCFNumber length]: unrecognized selector sent to instance 0x68732c0
2012-07-17 01:44:51.015 Calculator[9470:f803] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSCFNumber length]: unrecognized selector sent to instance 0x68732c0'
*** First throw call stack:
(0x13ca022 0x155bcd6 0x13cbcbd 0x1330ed0 0x1330cb2 0x12d2d18 0x13460d7 0x1397a8d 0x3a50 0x27ed 0x13cbe99 0x1714e 0x170e6 0xbdade 0xbdfa7 0xbd266 0x3c3c0 0x3c5e6 0x22dc4 0x16634 0x12b4ef5 0x139e195 0x1302ff2 0x13018da 0x1300d84 0x1300c9b 0x12b37d8 0x12b388a 0x14626 0x1ed2 0x1e45 0x1)
terminate called throwing an exception
I looked through apple's developer's document, saw 'NSString stringWithFormat:' method, and decided to use this method instead:
+ (NSString *)descriptionOfExpression:(id)anExpression{
NSMutableString *result = [NSMutableString string];
for (int i = 0;i<[anExpression count];i++){
[result appendString:[NSString stringWithFormat:#"%#",[anExpression objectAtIndex:i]]];
}
return result;
}
and it works now.
now I'm confused why second code works but the first doesn't.
I thought appending string only fails(and crashes) when it's passed a nil...
Is there something I'm missing?
Thank you in advance :)
It looks like the contents of anExpression are instances of NSNumber instead of NSString. The error you are getting is a hint as to how appendString works; it's first step is obviously to ask the passed "string" how long it is (presumably so it can allocate enough memory). This is obviously not a method on NSNumber (hence the crash) and stringWithFormat is designed to do type-checking and be more flexible.
I suspect you could also use stringValue just as well:
[result appendString:[[anExpression objectAtIndex:i] stringValue]];
+ (NSString *)descriptionOfExpression:(id)anExpression{
NSMutableString *result = [NSMutableString string];
for (int i = 0;i<[anExpression count];i++) {
[result appendString:[[anExpression objectAtIndex:i] stringValue]];
}
return result;
}
Converting it into string would help you!!
Use this function:
+ (NSString *)descriptionOfExpression:(id)anExpression
{
NSMutableString *result = [[NSMutableString alloc] init];
for (int i = 0;i<[anExpression count];i++)
{
NSString *str = [NSString stringWithFormat:#"%#",[anExpression objectAtIndex:i]];
if(str)
{
[result appendString:str];
}
//OR
//[result appendFormat:[NSString stringWithFormat:#"%#",[anExpression objectAtIndex:i]]];
}
return result;
}
I have an array which I store different classes which again hold different arrays. All arrays are defined as NSMutabelArrays.
When I want to delete an object in an array, my app crashes. This is my code:
NSLog(#"string to be deleted:%#", [[[self.myLibrary objectAtIndex:self.currentNoteBookNumber] tabReference] objectAtIndex:tid]);
NSLog(#"string to be deleted:%#", [[[self.myLibrary objectAtIndex:self.currentNoteBookNumber] tabColours] objectAtIndex:tid]);
NSLog(#"string to be deleted:%#", [[[self.myLibrary objectAtIndex:self.currentNoteBookNumber] tabTitles] objectAtIndex:tid]);
[[[self.myLibrary objectAtIndex:self.currentNoteBookNumber] tabReference] removeObjectAtIndex:tid];
[[[self.myLibrary objectAtIndex:self.currentNoteBookNumber] tabColours] removeObjectAtIndex:tid];
[[[self.myLibrary objectAtIndex:self.currentNoteBookNumber] tabTitles] removeObjectAtIndex:tid];
And this is the console output:
2011-05-01 22:03:40.788 M[61452:207] string to be deleted:2
2011-05-01 22:03:40.789 M[61452:207] string to be deleted:Orange
2011-05-01 22:03:40.791 M[61452:207] string to be deleted:Art
2011-05-01 22:03:40.806 M[61452:207] *** Terminating app due to uncaught exception 'NSRangeException', reason: '*** -[NSMutableArray objectAtIndex:]: index 0 beyond bounds for empty array'
I don't really know what I'm doing wrong. There is obviously something in the array, so it shouldn't be 0. I mean it is the ONLY thing stored in the array at the moment, but that shouldn't be a problem, I guess?
I'd be very grateful for any help on this.
EDIT:
I think I haven't provided enough code. This is the method in which I set up myLibrary:
-(void) setupLibrary {
myLibrary = [[NSMutableArray alloc] init];
NoteBook *newNoteBook = [[NoteBook alloc] init];
newNoteBook.titleName = #"TEST";
NSMutableArray *ttArray = [[NSMutableArray alloc] init];
[ttArray addObject:#"Art"];
NSMutableArray *tcArray = [[NSMutableArray alloc] init];
[tcArray addObject:#"Orange"];
NSMutableArray *trArray = [[NSMutableArray alloc] init];
[trArray addObject: [NSNumber numberWithInteger:2]];
newNoteBook.tabTitles = ttArray;
newNoteBook.tabColours = tcArray;
newNoteBook.tabReference = trArray;
[myLibrary addObject:newNoteBook];
currentNoteBookNumber = 0;
[newNoteBook release];
[ttArray release];
[tcArray release];
[trArray release];
}
Now it appears that if I delete, for instance, one object in the tabTitles array (e.g. "Art"), I delete the entire newNoteBook object. I.e. once I delete a string in tabTitles, all other strings at the same position in tabColours or tabReference will be deleted as well. Why is this so?
The following code will crash after I successfully deleted the string # position 0 in an array in my class which is stored in another array:
NSLog(#"string deleted:%#", [[[self.myLibrary objectAtIndex:0] tabReference] objectAtIndex:0]);
[[[self.myLibrary objectAtIndex:0] tabReference] removeObjectAtIndex:0];
NSLog(#"string deleted:%#", [[[self.myLibrary objectAtIndex:0] tabColours] objectAtIndex:0]);
[[[self.myLibrary objectAtIndex:0] tabColours] removeObjectAtIndex:0];
Don't know what's the problem here, but you should consider to keep your arrays safe:
if([yourArray count] > tid) {
[yourArray removeObjectAtIndex.tid;
}
Your error
-[NSMutableArray objectAtIndex:]: index 0
is telling that you are trying to get an object at index 0 not that you want to remove it. So I think what you did is you called the method where you have your reading and removing code 2 times in a row. Try to see it that is the case.
I have a method with the following code:
NSMutableArray *pickerArray = [[NSMutableArray alloc] init];
int i;
for(i = 1; i <= 7; i++) {
NSString *myString = [NSString stringWithFormat:#"%#", i];
[pickerArray addObject:myString];
}
for(i = 1; i <= 7; i++) {
NSString *fieldName = [[NSString alloc] initWithFormat:#"column%d", i];
[self setValue:pickerArray forKey:fieldName]; // setValue or initWithArray ???
[fieldName release];
[pickerArray release];
}
srandom(time(NULL));
When I build the application everything builds correctly but it crashes on start in the console i get the following error:
* -[NSCFString superview]: unrecognized selector sent to instance 0x380da90
* Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[NSCFString superview]: unrecognized selector sent to instance 0x380da90'
If instead of using an array containing strings I use UIImageView containing UIImages then everything works correctly...
I only would like to populate my picker with an array of numbers from 1 to 50...
Any help would be really appreciated... this thing is driving me mad :)
I don't think you want [myString release]; in your first for loop as the string you create is auto-released (rule of thumb, anything that is created without alloc, init, or new is auto-released)
Problem solved.... was something to do with the number of element in the pickerview, nothing to do with the method itself! Thanks anyway!
i try to append from NSMutableArray but the below exception, actually first 2 loop its giving result but the 3rd loop giving this exception
2009-12-04 12:01:19.044 AppBuzz[14562:207] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[NSCFString appendString:]: nil argument'
2009-12-04 12:01:19.057 AppBuzz[14562:207] Stack: (
820145437,
837578260,
819694387,
819694291,
814894619,
814804961,
17445,
23977,
18651,
19281,
862009284,
9035,
861597328,
861596264,
861928960,
861926972,
861925524,
858687888,
819893547,
819891231,
861592584,
861585968,
8749,
8612
)
terminate called after throwing an instance of 'NSException'
my code as below
for (int i = 0; i < [student count]; i++)
{
if([student objectAtIndex:i] != NULL)
{
dic = [student objectAtIndex:i];
tempName = [dic objectForKey:#"NAME"];
tempAvgMark = [[dic objectForKey:#"AVG_MARK"] intValue];
[data appendString:#"{\"name\":\""];
[data appendString:tempName]; // here i'm having prob
[data appendString:#"\",\"avg_mark\":\""];
//[data appendString:tempAvgMark];
[data appendString:#"\"}"];
}
}
NSLOG(#"Result - %#",data);
can anyone help for
1) to append [data appendString:tempName];
2) to append int value ([data appendString:tempAvgMark]; ) into data
thanks
You're trying to append a nil, which is illegal. You can easily get around this by changing the line in question to the following:
[data appendString:(tempName == nil ? #"" : tempName)];
Or replace that empty string with whatever else you want. To append a non-string value, convert it to a string like this:
[data appendString:[NSString stringWithFormat:#"%i", tempAvgMark]];
If tempAvgMark is not an 'int', you'll have to change the %i. For example, for NSNumbers, use %# instead.
The object for the key #"NAME" in the dictionary has to be a string, and to append an int you can use [string appendFormat:#"%d", someInt].
It appears from this message: NSCFString appendString:]: nil argument' that one of the dictionary values is null