In Java, this is not the case as far as I know. However, when working with regular expressions in .NET, be weary of just slapping /d in when you need a number alone. Just like Char.IsDigit isn't just numbers, /d follows suit.
The reason is that /d and Char.IsDigit are both validating against the Unicode designation "Nd". This stands for number decimal digit, but does not limit itself to just 0-9.
If you're using regular expressions to begin with, you probably already realize that it is fairly easy to correct this. All it takes is to use [0-9] instead of /d.