Regex to extract minute and seconds - iphone

Question

How can I extract minutes and seconds from a NSString? Examples:
3'15" or 3' 15" (3 minutes 15 seconds)
28" (28 seconds)
2' (2 minutes)
50 (default is in seconds, 50 seconds)
and stores into two NSIntegers?

Answer 1

Not entirely convinced that RegEx matching is the best way to read numbers out of a string, but here is a snippet that works:
NSString *str = #"12'34\"";
NSString *minutePattern = #"[[:digit:]]+'";
NSString *secondPattern = #"[[:digit:]]+\"?";
NSRange minuteRange = [str rangeOfString: minutePattern options: NSRegularExpressionSearch];
NSRange secondStartRange;
NSString *minuteString = #"";
if ( minuteRange.location != NSNotFound)
{
minuteString = [str substringWithRange: minuteRange];
NSUInteger secondStartPt = NSMaxRange(minuteRange);
secondStartRange = NSMakeRange(secondStartPt, str.length - secondStartPt);
}
else {
secondStartRange = NSMakeRange(0, str.length);
}
NSRange secondRange = [str rangeOfString: secondPattern
options: NSRegularExpressionSearch
range: secondStartRange];
NSString *secondString = #"";
if ( secondRange.location != NSNotFound)
{
secondString = [str substringWithRange: secondRange];
}
NSInteger minutes = [minuteString integerValue];
NSInteger seconds = [secondString integerValue];
NSLog(#"Minutes: %d, seconds: %d", minutes, seconds);
Note that it will parse a string like 5'21 as 5 minutes 21 seconds, not sure if that is what you want, but that can be fixed with an extra test.

Answer 2

NSArray *data = #[#"3'15\"", #"3' 15\"", #"28\"", #"2'", #"50"];
NSString *pattern = #"(\\d++')|(\\d++(\"{0,1})$)";
NSRegularExpression *regExp = [NSRegularExpression regularExpressionWithPattern:pattern
options:NSRegularExpressionCaseInsensitive
error:nil];
for (NSString *string in data) {
NSInteger mi = 0;
NSInteger ss = 0;
NSArray *match = [regExp matchesInString:string options:0 range:NSMakeRange(0,string.length)];
for (NSTextCheckingResult *result in match) {
NSString *value = [string substringWithRange:result.range];
if ([value hasSuffix:#"'"]) {
mi = [value integerValue];
} else {
ss = [value integerValue];
}
}
NSLog(#"%# - %d %d",string,mi,ss);
}