Count the amount of times '$' shows up in a string (Objective C) - objective-c

Question

I was wondering if there was an easy method to find the amount of times a character such as '$' shows up in a string in the language objective-c.
The real world example I am using is a string that would look like:
542$764$231$DataEntry
What I need to do is first:
1) count the amount of times the '$' shows up to know what tier the DataEntry is in my database (my database structure is one I made up)
2) then I need to get all of the numbers, as they are index numbers. The numbers need to be stored in a NSArray. And I will loop through them all getting the different indexes. I'm not going to explain how my database structure works as that isn't relevant.
Basically from that NSString, I need, the amount of times '$' shows up. And all of the numbers in between the dollar signs. This would be a breeze to do in PHP, but I was curious to see how I could go about this in Objective-C.
Thanks,
Michael

Answer 1

[[#"542$764$231$DataEntry" componentsSeparatedByString:#"$"] count]-1

Answer 2

The componentsSeparatedByString suggested by #Parag Bafna and #J Shapiro or NSRegularExpression e.g.:
#import <Foundation/Foundation.h>
int main(int argc, char *argv[]) {
#autoreleasepool {
NSError *error = NULL;
NSString *searchText = #"542$764$231$DataEntry";
NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:#"(\\d{3})\\$" options:NSRegularExpressionCaseInsensitive error:&error];
NSUInteger numberOfMatches = [regex numberOfMatchesInString:searchText options:0 range:NSMakeRange(0, [searchText length]) ];
printf("match count = %ld\n",numberOfMatches);
[regex enumerateMatchesInString:searchText
options:0
range:NSMakeRange(0,[searchText length])
usingBlock:^(NSTextCheckingResult *match, NSMatchingFlags flags, BOOL *stop){
NSRange range = [match rangeAtIndex:1];
printf("match = %s\n",[[searchText substringWithRange:range] UTF8String]);
}];
}
}
The componentsSeparatedByString is probably the preferred approach and much more performant where the pattern has simple repeating delimiters; but I included this approach for completeness sake.

Answer 3

Try this code:
NSMutableArray* substrings=[NSMutableArray new];
// This will contain all the substrings
NSMutableArray* numbers=[NSMutableArray new];
// This will contain all the numbers
NSNumberFormatter* formatter=[NSNumberFormatter new];
// The formatter will scan all the strings and estabilish if they're
// valid numbers, if so it will produce a NSNumber object
[formatter setNumberStyle: NSNumberFormatterDecimalStyle];
NSString* entry= #"542$764$231$DataEntry";
NSUInteger count=0,last=0;
// count will contain the number of '$' characters found
NSRange range=NSMakeRange(0, entry.length);
// range is the range where to check
do
{
range= [entry rangeOfString: #"$" options: NSLiteralSearch range: range];
// Check for a substring
if(range.location!=NSNotFound)
{
// If there's not a further substring range.location will be NSNotFound
NSRange substringRange= NSMakeRange(last, range.location-last);
// Get the range of the substring
NSString* substring=[entry substringWithRange: substringRange];
[substrings addObject: substring];
// Get the substring and add it to the substrings mutable array
last=range.location+1;
range= NSMakeRange(range.location+range.length, entry.length-range.length-range.location);
// Calculate the new range where to check for the next substring
count++;
// Increase the count
}
}while( range.location!=NSNotFound);
// Now count contains the number of '$' characters found, and substrings
// contains all the substrings separated by '$'
for(NSString* substring in substrings)
{
// Check all the substrings found
NSNumber* number;
if([formatter getObjectValue: &number forString: substring range: nil error: nil])
{
// If the substring is a valid number, the method returns YES and we go
// inside this scope, so we can add the number to the numbers array
[numbers addObject: number];
}
}
// Now numbers contains all the numbers found