Finding non-spacing characters in Objective-C

Question

How do I check if a character in my NSString is a non-spacing character?

For example:

NSString *string3 = @"เบียร์เหล้า";
//                    12345678 <- only take up 8 spaces

The NSString length is 11, but actually the space that it occupies is 8.

In Java, they can check the character type using code below:

static boolean isMark(char ch)
{
    int type = Character.getType(ch);
    return type == Character.NON_SPACING_MARK ||
           type == Character.ENCLOSING_MARK ||
           type == Character.COMBINING_SPACING_MARK;
}

What about Objective-C?

Thanks to bdash.

NSCharacterSet *characterSet = [NSCharacterSet nonBaseCharacterSet];

for (int i = 0; string3.length > i; i++)
{
    NSString *string = [string3 substringWithRange:NSMakeRange(i, 1)];
    NSRange letterRange = [string rangeOfCharacterFromSet:characterSet];
    if (letterRange.location != NSNotFound)
    {
        NSLog(@"non base character set");
    }
    else
    {
        NSLog(@"normal");
    }
}

You will find out which character that is not occupying space. Another way, you can find out the total non spacing character with code below.

NSString *newString = [[string3 componentsSeparatedByCharactersInSet:
                            [[NSCharacterSet nonBaseCharacterSet] invertedSet]] componentsJoinedByString:@""];

So for this example, the newString length is 3. That's what I'm looking for. Thanks people.

Answer 1

You can use [NSCharacterSet nonBaseCharacterSet] to retrieve the set of characters in the Unicode mark category. NSCharacterSet provides the ability to test whether a given character is a member of the set, and NSString provides the ability to find particular characters within a string that are (or aren't) members of a given NSCharacterSet.