In data flow coverage, does returning a variable use it?

问题

I have a small question in my mind. I researched it on the Internet but no-one is providing the exact answer. My question is:

In data flow coverage criteria, say there is a method which finally returns variable x. When drawing the graph for that method, is that return statement considered to be a use of x?

回答1:

Yes, a return statement uses the value that it returns. I couldn't find an authoritative reference that says so in plain English either, but here are two arguments:

• A return statement passes control from one part of a program to another, just like a method call does. The value being returned is analogous to a function parameter. return therefore is a use just like being a function parameter is a use.

• The other kind of use in data flow analysis is when a value leaves the program and has some effect on the outside world, for example by being printed. If we're analyzing a method, rather than an entire program, return causes the value to leave the scope which we're analyzing. So it's a use for the same reason that printing is a use.

来源：https://stackoverflow.com/questions/32908375/in-data-flow-coverage-does-returning-a-variable-use-it