3.2 Syntax

A word is a sequence of arbitrary characters (except white space). Words are separated by white space. E.g., each of the following lines contains exactly one word:

     word
     !@#$%^&*()
     1234567890
     5!a

A frequent beginner's error is to leave away necessary white space, resulting in an error like `Undefined word'; so if you see such an error, check if you have put spaces wherever necessary.

     ." hello, world" \ correct
     ."hello, world"  \ gives an "Undefined word" error

Gforth and most other Forth systems ignore differences in case (they are case-insensitive), i.e., `word' is the same as `Word'. If your system is case-sensitive, you may have to type all the examples given here in upper case.