My code is as follows:
NSArray *modifyVersionOnDevice [FileHandler parseFile:devicepath];
NSString *param = [modifyVersionOnDevice objectAtIndex:1];
//param at this point is one element with string of "#MAJREV: 3"
//As soon as I run the next line, I get an error Unrecognized selector sent
to instance.
NSArray *d =[param componentsSeparatedByString:#":"];
If I hard code
NSString *param =#"#MAJREV: 3"; it works
Turns out you have to convert param into a literal string.
NSString *param = [NSString stringWithFormat:#"%#",[modifyVersionOnDevice objectAtIndex:1]];
Then
NSArray *d =[param componentsSeparatedByString:#":"];
Related
I have a string like so:
NSString *path = #"\\fake\aaa\bbb\ccc\ddd\eee.pdf";
and I split the string into an array like so:
NSArray *array = [path componentsSeparatedByString:#"\"];
Now there are two things I need here.
I need a string with everything except eee.pdf
I need the last item in the array as a string (eee.pdf)
How would I do this?
Just for fun, there is a little-known way to get an NSURL with its benefit from a windows file path
NSString *path = #"\\\\fake\\aaa\\bbb\\ccc\\ddd\\eee.pdf";
NSURL *url = CFBridgingRelease(CFURLCreateWithFileSystemPath(kCFAllocatorDefault, (CFStringRef)path, kCFURLWindowsPathStyle, false));
NSString *fileName = url.lastPathComponent;
NSString *parentDirectory = url.URLByDeletingLastPathComponent.path;
Finally you have to convert parentDirectory back to windows path style (backslashes).
But if you mean POSIX paths used in OS X, it's much easier
NSString *path = #"/fake/aaa/bbb/ccc/ddd/eee.pdf";
NSURL *url = [NSURL fileURLWithPath:path];
NSString *fileName = url.lastPathComponent;
NSString *parentDirectory = url.URLByDeletingLastPathComponent.path;
I think you're trying to get the filepath and filename from a full path. There are better ways of doing that. But since you simply asked for the question, here's my answer. Please note that this is not the best approach. In addition, you have to escape the backslashes by using a preceding backslash.
NSString *path = #"\\fake\\aaa\\bbb\\ccc\\ddd\\eee.pdf";
NSArray *array = [path componentsSeparatedByString:#"\\"];
NSMutableArray *removedArray = [[NSMutableArray alloc] init];
for(int i=0; i< array.count -1; i++){
[removedArray addObject:[array objectAtIndex:i]];
}
NSString *joinedString =[removedArray componentsJoinedByString:#"\\"];
NSString *fileName = [array lastObject];
NSLog(#"Path: %#", joinedString);
NSLog(#"Filename: %#", fileName);
For the last element use the lastObject property of the NSArray.
For a string without the last element use subarrayWithRange: using array.count-1 for the NSRange length.
Then join the remaining array with componentsJoinedByString:.
NSString *fileName = [array lastObject];
NSArray *newArray = [array subarrayWithRange:NSMakeRange(0, array.count-1)];
NSString *directoryPath = [newArray componentsJoinedByString:#"\\"];
I know this has been asked before, but there is no answer that I have found useful.
First off here is my code
// load the .csv file with all information about the track
NSError *error;
NSString *filepath = [[NSBundle mainBundle] pathForResource:#"file" ofType:#"csv" inDirectory:nil];
NSString *datastring1 = [NSString stringWithContentsOfFile:filepath encoding:NSUTF8StringEncoding error:&error];
NSArray *datarow = [datastring1 componentsSeparatedByString:#"\r"];
//fill arrays with the values from .csv file
NSArray *data_seg = [datarow objectAtIndex:0]; //segment number
NSArray *data_slength = [datarow objectAtIndex:1]; //strait length
NSArray *data_slope = [datarow objectAtIndex:2]; //slope
NSArray *data_cradius = [datarow objectAtIndex:3]; //circle radius
NSArray *data_cangle = [datarow objectAtIndex:4]; //circle angle
NSLog(#"%i", [data_seg count]);
Okay, so there is the code, and I read that is has something to do with autorelease, but I was not able to add a retain like NSArray *data_seg = [[datarow objectAtIndex:0] retain]
When I run the code, I get [__NSCFString count]: unrecognized selector sent to instance 0x9d1ad50
Any help is appreciated, I'm not good at programming, and I am very new.
componentsSeparatedByString method returns an NSArray of NSString. Every item that you extract from datarow array is an NSString and an NSString doesn't respond to 'count'. Your code starting at //fill arrays is incorrect. Every objectAtIndex call will return an NSString*.
This is another way of saying that the datatype for data_seg is NSString* (not NSArray*).
With the corrected code snippet, the problem is because data_seg is a string, and -count is not a method of NSString. It seems you think data_seg is an NSArray.
Look at the documentation for -[NSString componentsSeparatedByString:] and see what it returns -- strings! So you get back an array of strings. So what you want is:
NSString *data_seg = [datarow objectAtIndex:0]; //segment number
NSLog(#"my segment number is: %#", data_seg);
Can you please tell me the file string entered in the array, and then you have to change an element in this array. doing so:
NSMutableArray *user;
...
NSString* filePath1 = #"user";
NSString* fileRoot1 = [[NSBundle mainBundle] pathForResource:filePath1 ofType:#"txt"];
NSString* fileContents1 =[NSMutableString stringWithContentsOfFile:fileRoot1 encoding:NSUTF8StringEncoding error:nil];
user = [fileContents1 componentsSeparatedByCharactersInSet:[NSCharacterSet newlineCharacterSet]];
money= [user[0] intValue]-2;
user[0]=[NSString stringWithFormat:#"%d",money];
swears
- [__NSArrayI ReplaceObjectAtIndex: withObject:]: unrecognized selector sent to instance 0x12fd4270
The componentsSeparatedByCharactersInSet: return a NSArray even if you local variable is a mutable array the value returned is not. So you will need to create a mutable copy.
Just can easily do this by call the mutableCopy on NSArray:
user = [[fileContents1 componentsSeparatedByCharactersInSet:[NSCharacterSet newlineCharacterSet] mutableCopy];
Someone use the following to initialize the NSstring
NSString *astring = [[NSString alloc] init];
I am wondering why not just use
NSString *atring = nil or NSString *astring = #""
There is no semantic difference between NSString *astring = [[NSString alloc] init]; and NSString *astring = #""; - but NSString *astring = nil; is completely different. The first two produce a reference to an immutable string value, the last indicates the absence of a value.
Whether the various ways of generating an zero-length string produce different objects is entirely an implementation detail. The code:
NSString *a = [[NSString alloc] init];
NSString *b = [NSString new];
NSString *c = #"";
NSString *d = [NSString stringWithString:#""];
NSLog(#"%p, %p, %p, %p, %p", a, b, c, d, #""); // %p = print the value of the reference itself
outputs (the exact values will vary):
0x7fff7100c190, 0x7fff7100c190, 0x1000028d0, 0x1000028d0, 0x1000028d0
showing only 2 zero-length string objects were created - one for #"" and one for alloc/init. As the strings are immutable such sharing is safe, but in general you should not rely on it and try to compare strings using reference comparison (==).
NSString *atring = nil
is different -- it's a nil pointer, not an empty string.
NSString *astring = #""
is almost the same, if you change it to something like
NSString* astring=[#"" retain];
It's one of the things that "don't matter"; he or she simply used one way. Probably for no particular reason at all.
NSString *atring = nil; is simply setting the pointer to nil and does nothing other than ensure that pointer is set to nil;
NSString *astring = #""; is a shorthand literal and is the equivalent of [NSString stringWithString:#""];
On another point I don't know why you would want to initialize a string to nothing if its not mutable since you won't be able to change it later without overriding it.
I'm able to successfully parse the contents of a XML file using TouchXML, but when I try to read an individual NSString, from the NSMutableArray that stores the parsed content, the iPhone app crashes.
My NSLog shows me that the file has been parse as it should, giving this output:
(
{
href = "mms://a19349.l412964549958.c41245496.f.lm.akamaistream.net/D/194359/4125596/v0001/reflector:49944";
},
{
href = "mms://a4322.l4129624350471.c414645296.a.lm.akamaistream.net/D/473432/4129566/v0001/reflector:546441";
} )
Here is the code I'm using to do the parsing:
NSMutableArray *res = [[NSMutableArray alloc] init];
.... Parsing happens here ....
Then I try to retrieve the string from the NSMutableArray, using this code (and the app crashes when trying to read this line of code, posted below NSMutableString *string1 = [NSMutableString stringWithString:url];
NSString *url = [[NSString alloc] init];
url = [res objectAtIndex:0];
NSMutableString *string1 = [NSMutableString stringWithString:url];
[string1 deleteCharactersInRange: [string1 rangeOfString: #"href = "]];
[string1 deleteCharactersInRange: [string1 rangeOfString: #";"]];
NSLog(#"Clean URL: %#", string1);
Please, how can I solve this problem? Thank you!
TouchXML returns you an array of NSDictionaries. In order to extract string you need to take value from this NSDictionary:
NSString *url = [[res objectAtIndex:0] objectForKey:#"href"];