Foobar

Foobar, and sometimes foo and bar separately, are common placeholder names in computing. 

Foobars have been used to name variables, functions, and commands whose exact identity is unimportant. For example, a JavaScript tutorial might explain that two variables can be created at once with the code var foo, bar = 5. It's a lot like the placeholder letters x and y in algebra.

 References 

Category:Computing