A metasyntactic variable is a type of variable used by application developers as a placeholder name or alias term. It is unlike more commonly used logical variables and may contain any symbol or word that does not violate the rules of the language, although most metasyntactic variables are nonsensical words selected for uniqueness.
Variable name creation is challenging, especially for programmers who teach specific programming language syntax or algorithms. Metasyntactic variable naming is used a temporary solution that provides greater clarity than random letters or words.
The following are examples of common metasyntactic variables:
- MIT/Stanford: foo, bar, baz, guux
- CMU: foo, bar, thud, grunt
- Python programmers: spam, ham eggs
- Common in England: o oogle, foogle, boogle o zork, gork, bork
Of all metasyntactic variables, "foo" is the most common.