occurrence of a character in a NSString - iphone

Question

I am googling NSSting manipulation methods from last few hours. and found many on stack overflow like this here
I have a String "1800 Ellis St, San Francisco, CA 94102, USA". String may have any number of "," . I have to take the third last(San Franncisco) and last(USA) substring after ",".
and output should be "San Franncisco USA".
I have logic how to do this in my mind that but I am struggling to implement it.
I try this code for getting the position of last three "," in string. but it's not work for me
NSInteger commaArr[3];
int index=0;
int commaCount=0;
for(unsigned int i = [strGetCityName length]; i > 0; i--)
{
if([strGetCityName characterAtIndex:i] == ',')
{
commaArr[index]=i;
index++;
++commaCount;
if(commaCount == 3)
{
break;
}
}
}
Thanks

Answer 1

You can do it like this:
NSString *s = #"1800 Ellis St, San Francisco, CA 94102, USA";
NSArray *parts = [s componentsSeparatedByString:#","];
NSUInteger len = [parts count];
NSString *res;
if (len >= 3) {
res = [NSString stringWithFormat:#"%#%#", [parts objectAtIndex:len-3], [parts objectAtIndex:len-1]];
} else {
res = #"ERROR: Not enough parts!";
}
The componentsSeparatedByString: will split the string at ,, and stringWithFormat: will put the parts back together.

Answer 2

NSString *s = #"1800 Ellis St, San Francisco, CA 94102, USA";
NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:#"^(?:[^,]*,)?\\s*([^,]*),\\s*(?:[^,]*),\\s*([^,]*)$" options:0 error:NULL];
NSString *result = [regex stringByReplacingMatchesInString:s options:0 range:NSMakeRange(0, [s length]) withTemplate:#"'$1 $2'"];

Answer 3

Try this:
NSString *string = #"1800 Ellis St, San Francisco, CA 94102, USA";
NSArray *components = [string componentsSeparatedByString:#","];
NSString *sanFrancisco = [components objectAtIndex:components.count - 3];
NSString *usa = [components objectAtIndex:components.count - 1];
NSString *result = [sanFrancisco stringByAppendingString:usa];