Question

The issue I have is that I want to parse strings in order, so for instance, parsing “one three two”, adding that to another string, and printing “one three two”. I’m using rangeOfString:, but when I parse that string, it returns “one two three”. I know that the order of parsing in my case is the placement of the if statements, but how do I parse that string in order? Here is my code:

NSString *string = @"one three two";
NSString *newString;

if ([string rangeOfString:@"one"].location != NSNotFound)
{
    newString = [newString stringByAppendingString:@"one"];
}
if ([string rangeOfString:@"two"].location != NSNotFound)
{
    newString = [newString stringByAppendingString:@"two"];
}
if ([string rangeOfString:@"three"].location != NSNotFound)
{
    newString = [newString stringByAppendingString:@"three"];
}

NSLog(@"%@",newString);

Answer 1

You are doing this wrong, you should use componentsSeparatedByString: and sorting:

NSString *stringWithNumbersOrdered(NSString *input)
{
    static NSArray *numberStrings = nil;

    if (!numberStrings)
    {
        numberStrings = [NSArray arrayWithObjects:@"zero", @"one", @"two", @"three", @"four", @"five", @"six", @"seven", @"eight", @"nine", /* etc. */ nil];
    }

    NSArray *components = [input componentsSeparatedByString:@" "];
    NSArray *componentsSorted = [components sortedArrayUsingComparator:^NSComparisonResult(id obj1, id obj2) {
        int value1 = [numberStrings indexOfObject:obj1];
        int value2 = [numberStrings indexOfObject:obj2];

        return value1 - value2;
    }];

    return [componentsSorted componentsJoinedByString:@" "];
}