Relevance for blank(empty) text file

what would be the relevance to identify blank(empty) text file ?

How about something like:

(size of files "foo.txt") = 0

thanks for the response Aram . how can i show the directory of file?
lets say, this “foo.txt” it is in the c:C:\itconfig\test

At least three ways:

1: (size of files "C:\itconfig\test\foo.txt") = 0
2: (size of files "foo.txt" of folders "C:\itconfig\test") = 0
3: (size of files "foo.txt" of folders "test" of folders "itconfig" of drive "C:\") = 0

but even blank text files have size greater than zero.

They shouldn’t, unless maybe you have an embedded space or newline character.