From QB64 Wiki
A question mark can be used as a substitute shortcut to typing PRINT when creating code.
Usage: ?"Hello world"
Result: PRINT "Hello world"
- When the IDE cursor moves to the next code line, the question mark is changed to PRINT and the prompt text and variable are spaced appropriately.
- When an INPUT statement has no text, a question mark will appear before the input.
- A semicolon after the INPUT prompt text will add a question mark after the statement.