Freepascal string to filename

[Zahuczky]

Hey guys. I have a question.
Is it possible in Freepascal, assign a variable as a filename? For example 
 
 

Var a:string;
       f:text;

Begin 
assign(f,a);
reset(f);

I just had my high-school exam from advanced IT, and usually when the filename has to be a variable, they state that in the task, that if it's not possible use any name. This wasn't there this year.
And to my knowledge, there's no way to use a variable as filename. 

[Zahuczky]

5 minutes ago, James Evens said:

File handling is done with objects. Doesn't matter if it is a stream or more advance parser like Image.loadfromfile(varPath). Those function require a String with the path when called/setup.

 

Could you please give me an example, or like an article for this? Even if it's possible, it might be harder than what is needed on the exam.