In informal English, the same inflection is usually notated by ending a sentence with first a question mark and then an exclamation mark, or vice versa. Many people are unfamiliar with the interrobang, and would be puzzled when first seeing it, although its intention is usually self-evident. The interrobang can be hand-written with a single stroke plus the dot. One common application is in cartoons, as a stand-alone symbol of surprise.
Is there a difference, or are they identical?