Most of the basic level programmers know the hello world programs but while the getting started with string concatenation they came through a non-familiar word “foobar”
What is that “foobar”
“Foo” and “bar” as metasyntactic variables were popularised by MIT and DEC, the first references are in work on LISP and PDP-1 and Project MAC from 1964 onwards.
Many of these people were in MIT’s Tech Model Railroad Club, where we find the first documented use of “foo” in tech circles in 1959 (and a variant in 1958).
Both “foo” and “bar” (and even “baz”) were well known in popular culture, especially from Smokey Stover and Pogo comics, which will have been read by many TMRC members.
Also, it seems likely the military FUBAR contributed to their popularity.