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];
Related
It may be a simple question, but i could't get the answer and needing your help!
I have a string like,
NSString *temp = #"Hello How are you?";
I have to provide spaces dynamically starting in this string by code. For ex: I need to dynamically add 5 spaces in this string in starting point. So, the output string will be like,
#" Hello how are you?"
My doubt is, how can i add spaces dynamically to a existing string? I need it to do this way only, not via any other way like string concatenation etc. due to my requirement.
So, please advise me how can i add spaces dynamically in starting point of the existing string.
Note: The spaces will vary every time, its not constant that i can provide 5 spaces only, it will vary.
Thank you!
An NSString is immutable, so you have to create a new string in any case.
The following code will create a front-padded string with padLength spaces:
int padLength = 10;
NSString* originalString = #"original";
NSString* leadingSpaces = [#"" stringByPaddingToLength:padLength];
NSString* resultString = [NSString stringWithFormat:#"%#%#", leadingSpaces, originalString];
I have this code:
// Fill out the email body text
NSString *emailBody = (#"Name:%#\nNumber of People:\nDate:", name.text);
NSLog(#"%#", emailBody);
As you can see I'm trying to append name.text to the e-mail body just after "Name:". However, NSLog only outputs the string contained in name.text and none of the rest of the e-mail body. What am I doing wrong here that the code deletes the rest of the string apart from name.text?
E.G if name.text contained the text "Jack", then NSLog would only output "Jack" and not:
Name: Jack
Number of People: x
Date: x
Which is what I am looking for.
Can anyone give me an insight as to what I'm doing wrong?
Thanks,
Jack
Use +stringWithFormat method:
NSString *emailBody = [NSString stringWithFormat:#"Name:%#\nNumber of People:\nDate:", name.text];
What you have now is a valid code, but it doesn't do what you want:
(#"Name:%#\nNumber of People:\nDate:", name.text);
calls a comma operator - it evaluates its 1st parameter, discards it and returns 2nd parameter, so that's why emailBody is eventually filled with name.text value
You should write
NSString *emailBody = [#"Name:%#\nNumber of People:\nDate:" stringByAppendingString:name.text];
Or, if it doesn't compile,
[[NSString stringWithString:#"Name:%#\nNumber of People:\nDate:"] stringByAppendingString:name.text]
generally you want to either use stringWithFormat as was suggested, which creates an autorelease string that follows the format you have, or you can use initWithFormat instead, which creates a string you can manually manage for better memory behavior, if necessary.
some books will insist that for the iphone, which has limited memory, you don't depend on autorelease objects more than it absolutely necessary, so you'd often find this instead:
NSString *emailBody = [[NSString alloc] initWithFormat:#"Name:%#\nNumber of People:\nDate:", name.text];
Then you can use "emailBody" and immediately after you are done with it, put in this line:
[emailBody release];
This is a good habit to get into in general.
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 use the following statement for into to NSString conversion (with a find/replace)
curr_rep_date = [tmpRptDt stringByReplacingOccurrencesOfString:tmpYrVal withString:[NSString stringWithFormat:(tmpCurrYearInt-1)]];
I have declared
int tmpYrVal;
NSMutableString *tmp_dt,*curr_rep_date;
But the program seems to be crashing and the debugger is not giving any hint.
Could someone help me with the issue and what would be the correct usage.
There's a number of problems here.
Firstly, sringByReplacingOcurrancesOfString:withString: is expecting NSStrings as parameters, not ints. That's the reason why it crashes. The method Is attempting to send a message to a primitive type, not an object.
Secondly, you need to use a proper format string for the stringWithFormat: method. This is the same as how NSLog works.
A format string can look like #"some text %d". It would then be followed by a comma separated list of values to be used in place of the % placeholders.
Example:
[NSString stringWithFormat:#"%d", myIntValue];
Will effectively turn your int into a string, as it creates a new string with a format using your int.
You invoked the stringWithFormat - Method without a format string. [NSString stringWithFormat: #"%i", (tmpCurrYearInt-1)] should solve your problem.
You are missing the format
curr_rep_date = [tmpRptDt stringByReplacingOccurrencesOfString:tmpYrVal withString:[NSString stringWithFormat:#"%d", (tmpCurrYearInt-1)]];
Basic int to NSString conversion works like this:
NSString* s = [NSString stringWithFormat:#"%d", intNumber];
Based on this SO question asked a few hours ago, I have decided to implement a swizzled method that will allow me to take a formatted NSString as the format arg into stringWithFormat, and have it not break when omitting one of the numbered arg references (%1$#, %2$#)
I have it working, but this is the first copy, and seeing as this method is going to be potentially called hundreds of thousands of times per app run, I need to bounce this off of some experts to see if this method has any red flags, major performance hits, or optimizations
#define NUMARGS(...) (sizeof((int[]){__VA_ARGS__})/sizeof(int))
#implementation NSString (UAFormatOmissions)
+ (id)uaStringWithFormat:(NSString *)format, ... {
if (format != nil) {
va_list args;
va_start(args, format);
// $# is an ordered variable (%1$#, %2$#...)
if ([format rangeOfString:#"$#"].location == NSNotFound) {
//call apples method
NSString *s = [[[NSString alloc] initWithFormat:format arguments:args] autorelease];
va_end(args);
return s;
}
NSMutableArray *newArgs = [NSMutableArray arrayWithCapacity:NUMARGS(args)];
id arg = nil;
int i = 1;
while (arg = va_arg(args, id)) {
NSString *f = [NSString stringWithFormat:#"%%%d\$\#", i];
i++;
if ([format rangeOfString:f].location == NSNotFound) continue;
else [newArgs addObject:arg];
}
va_end(args);
char *newArgList = (char *)malloc(sizeof(id) * [newArgs count]);
[newArgs getObjects:(id *)newArgList];
NSString* result = [[[NSString alloc] initWithFormat:format arguments:newArgList] autorelease];
free(newArgList);
return result;
}
return nil;
}
The basic algorithm is:
search the format string for the %1$#, %2$# variables by searching for %#
if not found, call the normal stringWithFormat and return
else, loop over the args
if the format has a position variable (%i$#) for position i, add the arg to the new arg array
else, don't add the arg
take the new arg array, convert it back into a va_list, and call initWithFormat:arguments: to get the correct string.
The idea is that I would run all [NSString stringWithFormat:] calls through this method instead.
This might seem unnecessary to many, but click on to the referenced SO question (first line) to see examples of why I need to do this.
Ideas? Thoughts? Better implementations? Better Solutions?
Whoa there!
Instead of screwing with a core method that you very probably will introduce subtle bugs into, instead just turn on "Static Analyzer" in your project options, and it will run every build - if you get the arguments wrong it will issue a compiler warning for you.
I appreciate your desire to make the application more robust but I think it very likely that re-writing this method will more likely break your application than save it.
How about defining your own interim method instead of using format specifiers and stringWithFormat:? For example, you could define your own method replaceIndexPoints: to look for ($1) instead of %1$#. You would then format your string and insert translated replacements independently. This method could also take an array of strings, with NSNull or empty strings at the indexes that don't exist in the “untranslated” string.
Your method could look like this (if it were a category method for NSMutableString):
- (void) replaceIndexPointsWithStrings:(NSArray *) replacements
{
// 1. look for largest index in "self".
// 2. loop from the beginning to the largest index, replacing each
// index with corresponding string from replacements array.
}
Here's a few issues that I see with your current implementation (at a glance):
The __VA_ARGS__ thingy explained in the comments.
When you use while (arg = va_arg(args, id)), you are assuming that the arguments are nil terminated (such as for arrayWithObjects:), but with stringWithFormat: this is not a requirement.
I don't think you're required to escape the $ and # in your string format in your arg-loop.
I'm not sure this would work well if uaStringWithFormat: was passed something larger than a pointer (i.e. long long if pointers are 32-bit). This may only be an issue if your translations also require inserting unlocalised numbers of long long magnitude.