CODEWITHSUNDEEP
objective-ciosnsstring
Sosily
Sosily

Reputation: 726

how to find number of images from file name?

i need to know how meny image's i have from the file name exp: i have images call: first file: Splash_10001.jpg last file: Splash_10098.jpg and i want to inset then to array.. 

 for(int i = 1; i <= IMAGE_COUNT; i++)
{
    UIImage* image = [UIImage imageNamed:[NSString stringWithFormat:@"%@%04d.%@",self.firstImageName,i,self.imageType]];
    NSLog(@"%d",i);
    [imgArray addObject:image];
}

i want to replace IMAGE_COUNT with number 98 but i need to get the numbre from the string the user send me : Splash_10098.jpg i need to Separate the Splash_10098.jpg into: nsstring:Splash_1 int:0098 nsstring:jpg 10x all!

Upvotes: 0

Views: 199

Answers (4)

iDev
iDev

Reputation: 23278

Using Regex(NSRegularExpression in iOS), this can be done very easily,

Check this out,

NSError *error = NULL;
NSString *originalString = @"Splash_10098.jpg";
NSString *regexString = @"([^\?]*_[0-9])([0-9]*)(.)([a-z]*)";

NSRegularExpression* regex = [NSRegularExpression regularExpressionWithPattern:regexString options:NSRegularExpressionCaseInsensitive error:&error];
NSTextCheckingResult *match = [regex firstMatchInString:originalString options:NSRegularExpressionCaseInsensitive range:NSMakeRange(0, [originalString length])];

NSLog(@"FileName: %@", [originalString substringWithRange:[match rangeAtIndex:1]]);
NSLog(@"Total Count: %@", [originalString substringWithRange:[match rangeAtIndex:2]]);
NSLog(@"File type: %@", [originalString substringWithRange:[match rangeAtIndex:4]]);

Result:

FileName: Splash_1
Total Count: 0098
File type: jpg

Upvotes: 0

Henri Normak
Henri Normak

Reputation: 4725

If the number length is fixed in the suffix, it would make sense to use a substring instead of trying to remove the prefix. Strip the extension and grab the last x characters, convert those into an int with either intValue or the NSNumberFormatter suggested by iOS, although that might be unnecessary if you are sure of the format of the string.

NSString *userProvidedString = @"Splash_10001.jpg";
NSString *numberString = [userProvidedString stringByDeletingPathExtension];
NSUInteger length = [numberString length];
NSInteger numberLength = 4;
if (length < numberLength)
{
     NSLog(@"Error in the string");
     return;
}
numberString = [numberString substringWithRange: NSMakeRange(length - 4, 4)];
NSInteger integer = [numberString integerValue];
// Do whatever you want with the integer.

Upvotes: 0

iOS
iOS

Reputation: 813

It depends what input are of the string is granted. In the following I would search for the dot and go backwards to the maximum of digits. By the way I could only recommend to use the multi lingual NumberFormatter instead of relying on the default conversion.

  NSString * input = @"Splash_19001.jpg";
  NSRange r = [input rangeOfString:@"."];
  if(r.location>4){
    NSString * numberPart = [input substringWithRange: NSMakeRange(r.location-4,4)];
    NSNumberFormatter *nf = [[NSNumberFormatter alloc] init];
    [nf setNumberStyle:NSNumberFormatterDecimalStyle];
    NSNumber * number = [nf numberFromString:numberPart];
    int val = [number intValue];
    NSLog(@"intValue=%d",val);
  }

Upvotes: 1

unsunghero
unsunghero

Reputation: 1001

I think this is what you're looking for

NSString *stringUserSendsYou = @"Splash_10098.jpg";
int IMAGE_COUNT = [[[stringUserSendsYou stringByReplacingOccurrencesOfString:@"Splash_1" withString:@""] stringByReplacingOccurrencesOfString:@".jpg" withString:@""] integerValue];

Upvotes: 0

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