An Objective-C function for parsing a comma-delimited line of text while preserving commas located within fields. End of the line is detected with either a '\n' newline character or the end of the character stream.

gistfile1.m

- (NSMutableArray *)parseCSVStringIntoArray:(NSString *)csvString {

    NSMutableArray *csvDataArray = [[NSMutableArray alloc] init];
   
    // break string into an array of individual characters
    NSMutableArray *characters = [[NSMutableArray alloc] initWithCapacity:[csvString length]];
    int csvStringLength = [csvString length];
    for (int c=0; c < csvStringLength; c++) {
        NSString *ichar  = [NSString stringWithFormat:@"%c", [csvString characterAtIndex:c]];
        [characters addObject:ichar];
    }
    
    BOOL quotationMarksPresent = FALSE;
    
    for (NSString *ichar in characters) {
        if ([ichar isEqualToString:@"\""]) {
            quotationMarksPresent = TRUE;
            break;
        }
    }
    
    if (!quotationMarksPresent) {
        // quotation marks are NOT present
        // simply break by comma and return
        
        NSArray *componentArray = [csvString componentsSeparatedByString:@","];
        csvDataArray = [NSMutableArray arrayWithArray:componentArray];
        
        return csvDataArray;
        
    } else {
        // quotation marks ARE present

        NSString *field = [NSString string];
        BOOL ignoreCommas = FALSE;
        int counter = 0;
        
        for (NSString *ichar in characters) {
            
            if ([ichar isEqualToString:@"\n"]) {
                // end of line reached
                [csvDataArray addObject:field];
                
                return csvDataArray;
            }
            
            if (counter == ([characters count]-1)) {
                // end of character stream reached
                // add last character to field, add to array and return
                field = [field stringByAppendingString:ichar];
                [csvDataArray addObject:field];
                
                return csvDataArray;
            }
            
            
            if (ignoreCommas == FALSE) {
                if ( [ichar isEqualToString:@","] == FALSE) {
                    // ichar is NOT a comma
                    
                    if ([ichar isEqualToString:@"\""] == FALSE) {
                        // ichar is NOT a double-quote
                        field = [field stringByAppendingString:ichar];
                    } else {   
                        // ichar IS a double-quote
                        ignoreCommas = TRUE;
                        field = [field stringByAppendingString:ichar];
                    }
                    
                } else {
                    // comma reached - add field to array
                    if ([field isEqualToString:@""] == FALSE) {
                        [csvDataArray addObject:field];
                        field = @"";
                    }
                    
                }
                
            } else {
                
                if ([ichar isEqualToString:@"\""] == FALSE) {
                    // ichar is NOT a double-quote
                    field = [field stringByAppendingString:ichar];
                } else {
                    // ichar IS a double-quote
                    // closing double-quote reached
                    ignoreCommas = FALSE;
                    field = [field stringByAppendingString:ichar];
                    // end of field reached - add field to array
                    if ([field isEqualToString:@""] == FALSE) {
                        [csvDataArray addObject:field];
                        field = @"";
                    }
                    
                }
                
            } // END if (ignoreCommas == FALSE)
            
            counter++;
        } // END for (NSString *ichar in characters)
        
    }
    
    return nil;
}