Retrieve only positive integers from a given string

Question

I have the following implementation where a comboKey is a string that I am trying to retrieve the integers.

For example if the comboKey is 2m1s and then it returns @[@"2",@"1"]; which is perfect.

If comboKey is 0m2s and then it returns @[@"0",@"2"];, however I do not want to have 0. I only want have positive number(s) @[@"2"];

+ (NSArray*)comboCategoryItems : (NSString*)comboKey
{        
  NSCharacterSet *nonDigitCharacterSet = [[NSCharacterSet decimalDigitCharacterSet] invertedSet];
  NSArray *outArray = [comboKey componentsSeparatedByCharactersInSet:nonDigitCharacterSet];
  outArray = [outArray filteredArrayUsingPredicate:[NSPredicate predicateWithFormat:@"length > 0"]];
  return outArray;
}

Answer 1

Here is another way to do this, using regular expressions

NSRegularExpression * exp = [[NSRegularExpression alloc]initWithPattern:@"([1-9]([0-9])*)+" options:NSRegularExpressionDotMatchesLineSeparators error:nil];
NSString * text = @"80m254s";
NSMutableArray *resultArray = [NSMutableArray array];
[exp enumerateMatchesInString:text options:NSMatchingWithoutAnchoringBounds range:NSMakeRange(0, text.length) usingBlock:^(NSTextCheckingResult * _Nullable result, NSMatchingFlags flags, BOOL * _Nonnull stop) {
    [resultArray addObject:[text substringWithRange:[result range]]];
}];


NSLog(@"%@",resultArray);

for @"0m2s"

2017-07-15 22:31:18.576397 RegexTestingProject[21823:1942182] ( 2 )

for @"80m254s"

2017-07-15 22:33:50.378485 RegexTestingProject[21826:1942829] ( 80, 254 )

for @"080m254s"

2017-07-15 22:35:40.760626 RegexTestingProject[21828:1943403] ( 80, 254 )

Hope this helps you

Answer 2

You you have done little bit mistake. In predicate you check string length rather than value. Just change the predicate like this @"integerValue > 0" your code will produce expected result.