I'm building a class to replace the old one online. We have old projects in php 5.3. And new php 5.6 and 7.0 projects. Developers wish to use new features such as 'yield' in new verions, but the class may also be included in old projects. Of cause, old projects can't run the code with yield, but it even can't parse the file. So do I have to write two different files?
I want to use this:
yield $key => $value;
p.s. if there's no '$key', I can simply write:
yield ($value);
This can be parsed in ver 5.3.
Thank you very much.