I want my app to do something when the last NSLog has a certain string. I thought I could realize this with an if-query and isEqualtoString, but how can I make this?
Sorry for my bad English ;)
Maybe I don't understand what you're trying to do, but you can just create the string somewhere, log it, and then test it:
NSInteger _someInt = 2;
NSString *_someString = #"bananas";
NSString *_stringToBeLogged = [NSString stringWithFormat:#"%d %#", _someInt, _someString];
NSLog(#"%#", _stringToBeLogged);
if ([_stringToBeLogged isEqualToString:#"2 bananas"]) {
NSLog(#"I logged two bananas...");
}
You could consider creating your own custom log function which calls NSLog() after checking for your string constant. This would keep your code a bit cleaner if you want this functionality in multiple places and also allows you to easily extend the logging function further if desired.
Related
this is hard to describe but I am currently catching a string from a database, this string can be 1-4 characters long, however I am wanting to always display 4 characters, so if i get say a string back that is 34, i want it to be 0034.
I have set up a method to catch the string so now I just need to figure out how to do this. what I then plan to do is feed that string into a NSArray so I can send each [i'th] of the array off to 4 differetn methods that control animations in my app.
The reason its in string format is because I have had to bounce it round from hex, to int to string for various formatting reasons within the application.
this is my code i have so far. Suggestions/solutions would be great thankyou, I am so new its hard to find solutions for stuff like string manipulation etc..
//... other method I am getting the string from/.
[self formatMyNumber:dataString];
///..
-(void)formatMyNumber:(NSString *)numberString{
//resultLabel.text = numberString; //check to make sure string makes it to here.
//NSLog(#"hello From formatMyNumber method"); //check
}
//..
//the with send off each character to 4 animation methods that accept integers.
- (void)playAnimationToNumber:(int)number{
//...
//UpDated... weird stuff happening.
here is my method so far.
//Number Formatter
-(void)formatMyNumber:(NSString *)numberString{
NSLog(#"This is what is passed into the method%#",numberString);
int tempInt = (int)numberString;
NSLog(#"This is after I cast the string to an int %i",tempInt);
//[NSString alloc] stringWithFormat:#"%04d", numberString];
NSString *tempString = [[NSString alloc] initWithFormat:#"%04d", tempInt];
NSLog(#"This is after I try to put zeros infront %#",tempString);
//resultLabel.text = tempString;
//NSLog(#"hello From formatMyNumber method");
}
this is the output.
[Session started at 2011-06-19
16:18:45 +1200.] 2011-06-19
16:18:54.615 nissanCode0.1[4298:207]
731 2011-06-19 16:18:54.616
nissanCode0.1[4298:207] 79043536
2011-06-19 16:18:54.617
nissanCode0.1[4298:207] 79043536
2011-06-19 16:18:54.617
nissanCode0.1[4298:207] hello From
formatMyNumber method
As far as the number of zeros preceding your string goes there are a couple of ways to do this. I'd suggest:
NSString *myString = [NSString stringWithFormat:#"%04d",[dataString intValue]];
Is it possible you could have the number in integer form instead of string form? If so, it's pretty easy to use [NSString stringWithFormat:#"%04d", number]. See here for a list of the possible format specifiers.
See what stringWithFormat: can do. I realize you mentioned your numbers are NSStrings, but if they were ints, or you convert them back to ints, the following may do the trick. Modify the following to best suit your need:
return [NSString stringWithFormat:#"%04d", number];
I am confused about strings (a beginner's problem, I'm afraid):
I have one NSMutableArray called Notebook. At index position 1, I have an object, which I think is a string. At least I put it into the array like this:
[NoteBook replaceObjectAtIndex:1 withObject:#"x-x-x-x"];
So far so good. If I put this into an UILabel, it will show x-x-x-x on my screen. The nightmare starts when I try to compare this string with other strings. Let's consider that I do not want to display the string x-x-x-x on my screen, but just to have a blank instead. So I thought I could achieve this by coding this:
NSString *tempDateString;
tempDateString = [NSString stringWithFormat:#"%#",[NoteBook objectAtIndex:1]];
if (tempDateString == #"x-x-x-x") {
UISampleLabel.text = #"";
}
For some reason, this does not work, i.e. even if the string at position 1 of my array is 'x-x-x-x', it will still not set my UISampleLabel to nothing.
I suppose that I am getting confused with the #"" markers. When do I really need them? Why can't I simply code tempDateString = [NoteBook objectAtIndex:1]; without the formatting thing?
Any help and suggestions would be very much appreciated!
You need to compare string with isEqualToString:
if ([tempDateString isEqualToString:#"x-x-x-x"]) {
UISampleLabel.text = #"";
}
In addition to the question that's been answered:
Why can't I simply code tempDateString = [NoteBook objectAtIndex:1]; without the formatting thing?
You can. Why do you think you can't?
I am programming an iPhone App which is supposed to parse a flat-file from the web, create managed objects from the flat-file and later on should display them in an UITableView.
There are no problems with the saving and the displaying, but I just can't get the hang of a good Parser.
Thats the file I want to parse: Flat-file
AS far as I know, I can't use the NSXMLParser for this task (because obviously there are no tags).
So I at first tried to programm a NSScanner which should get me the interesting properties --> didn't work out
Now I am using this method:
- (void) parseMemberDataWithURL: (NSString *)urlString
{
self.memberTempCounter = 1;
//Get data from web
self.downloadedText = [NSString stringWithContentsOfURL: [NSURL URLWithString: urlString] encoding:NSUTF8StringEncoding error:nil ];
memberArray = [downloadedText componentsSeparatedByString:#";"];
while (self.memberTempCounter<[memberArray count])
{
[[ExhibitorController sharedController] createExhibitorWithName:[memberArray objectAtIndex:self.memberTempCounter]
street:[memberArray objectAtIndex:self.memberTempCounter+2]
zip:[memberArray objectAtIndex:self.memberTempCounter+3]
city:[memberArray objectAtIndex:self.memberTempCounter+4]
email:[memberArray objectAtIndex:self.memberTempCounter+7]
phone:[memberArray objectAtIndex:self.memberTempCounter+5]
website:[memberArray objectAtIndex:self.memberTempCounter+8]
produktbereiche:[[memberArray objectAtIndex:self.memberTempCounter+9] componentsSeparatedByString:#","]];
self.memberTempCounter= self.memberTempCounter+13;
}
}
I am using the memberTempCounter to identify the property.
The problems are:
This only works out in like 3 of 4 times.1 of 4 times the App crashes and I have no Idea why...
The method has a performance like a 1962 VW Beetle. Parsing the whole chunk of data takes up to 3 Minutes on my iPhone 3G
Any Ideas or a simpler way to do this?
I would be really gratefull. Thanks in advance: -)
You might as well do all the parsing in the background, and then display as the information gets parsed.
As for memory issues, try doing temporary autorelease pools and release every 50 or so iterations through the loop.
int count = 0;
NSAutoreleasePool * loopPool = [[NSAutoreleasePool alloc] init];
while(someInsanelyLargeCondition){
// Do your stuff here
// .............
count++;
if (count > 50) {
count = 0;
[loopPool release];
loopPool = [[NSAutoreleasePool alloc] init];
}
}
Recursive-descent (LL1) parsers are pretty simple, light on memory, and for speed they go almost as fast as you can run a pointer through characters. Building your data structure would probably be the dominant time-taker.
I was finally able to fix my performance problem.
I have a method in another class, which ads Tags for the different Exhibitors. Therefore it first checks if the Tag already is stored in the database or else creates it.
With an growing Set of Tags in my database the search-process took longer and longer and this led to the long parsing time.
Anyone else having this problem: Take a look at the Performance Core Data Programming guide of apple in the "Implementing Find-or-Create Efficiently"-section:
http://developer.apple.com/mac/library/documentation/Cocoa/Conceptual/CoreData/Articles/cdImporting.html
#"/News/some news text/"
#"/News/some other news text/"
#"/About/Some about text/"
#"/Abcdefg/Some abcdefg text/some more abcdefg text"
How do I cut out the first part of the strings, so that I end up with the following strings?
#"/News/"
#"/News/"
#"/About/"
#"/Abcdefg/"
Use componentsSeparatedByString: to break the string up:
NSArray *components=[string componentsSeparatedByString:#"/"];
if ([components count]>=2) {
// Text after the first slash is second item in the array
return [NSString stringWithFormat:#"/%#/",[components objectAtIndex:1]];
} else {
return nil; // Up to you what happens in this situation
}
If these are pathnames, you may want to look into the path-related methods of NSString, such as pathComponents and pathByDeletingLastPathComponent.
While it's pretty unlikely that the path separator is ever going to change, it's nonetheless a good habit to not rely on such things and use dedicated path-manipulation methods in preference to assuming that the path separator will be a certain character.
EDIT from the year 2013: Or use URLs (more specifically, NS/CFURL objects), which Apple has made pretty clear are the proper way to refer to files from now on, and are necessary for some tasks in a sandbox.
I am having code
NSString *cellValue1 = [products1 objectAtIndex:indexPath.row];
when i try to print NSLog(#"cell value is %#",cellValue1);
in log i am not getting anything,
if i use %s, i am getting some symbols, not the string located in cellValue1.
Please help me.
Thanks in advance.
Check to make sure that products1 is actually set. It sounds as though it's nil when you send it the -objectAtIndex: message.
It surely means your string is empty...
Check it with the length method...
Solution:
NSString *cellValue1 = [products1 objectAtIndex:indexPath.row];
NSLog([NSString stringWithFormat:#"Cell Value is %#", cellValue1]);
Reason:
NSLog operates with String inputs. While your statement should work, if there is some/any issue with your original cellValue1 string, your original statement will not catch the issue and assure that that NSLog() is being handed a pure string. By using the stringWithFormat: syntax you assure that even if your cellValue1 values is null or nil, you will receive your "cell value is" comment and possible some hint as to what is being passed into the statement by your cellValue1 string.
Testing Note:
If the above doesn't work for you, Test your original string by just using NSLog(cellValue1);. If this doesn't work it will tell you that your original NSString is not properly pulling your product at indexPath.row values.
Hope this helps!