Getting the name of a variable in Java

Question

Is it possible to get the name of a variable in Java at runtime?

Possible use case: in assertions. Given an assertion like

assert percval >= 0 && percval <= 100 : "percval out of range: " + percval;

Depending on your IDE, if you refactor the code, rename the variable, it may not automatically change occurrences in strings. Possible result:

assert percentage >= 0 && percentage <= 100 : "percval out of range: " + percentage;

Would be nice if there was something like this:

assert percval >= 0 && percval <= 100 : nameOf(percval) + " out of range: " + percval;

Possible?

No, that's not possible in java. Reflection might get you the name of members, but not local variables. — f1sh
– f1sh, Commented Mar 15, 2017 at 10:49
I think you can achieve this by checking stackoverflow.com/questions/744226/… . — screab
– screab, Commented Mar 15, 2017 at 10:57
Possible duplicate of How do I print the variable name holding an object? — alain.janinm
– alain.janinm, Commented Mar 15, 2017 at 14:01
Did my answer solve your problem? I am curious because I did not use it self and wonder if it is possible with I have given link to ? — Ad Infinitum
– Ad Infinitum, Commented Mar 24, 2017 at 10:40
I didn’t try it either since the project still develops on Java 7 only. If it works, it would be what I was looking for. I will come to it later when switching to Java 8. I do not know when this will happen. — Matthias Ronge
– Matthias Ronge, Commented Mar 27, 2017 at 6:50

Ad Infinitum · Accepted Answer · 2017-03-15 13:40:14Z

I am not sure if it was possible before java 8 but with java 8, you can follow the following link and achieve what you want to do.

The summary of this is given as follows;

Provide a mechanism to easily and reliably retrieve the parameter names of methods and constructors at runtime via core reflection.

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