Determine original name of variable after its passed to a function

Question

I've got a feeling this might not be possible, but I would like to determine the original variable name of a variable which has been passed to a function in javascript. I don't know how to explain it any better than that, so see if this example makes sense.

function getVariableName(unknownVariable){
  return unknownVariable.originalName;
}

getVariableName(foo); //returns string "foo";
getVariableName(bar); //returns string "bar";

This is for a jquery plugin i'm working on, and i would like to be able to display the name of the variable which is passed to a "debug" function.

Answer 1

You're right, this is very much impossible in any sane way, since only the value gets passed into the function.

Answer 2

This is now somehow possible thanks to ES6:

function getVariableName(unknownVariableInAHash){
  return Object.keys(unknownVariableInAHash)[0]
}

const foo = 42
const bar = 'baz'
console.log(getVariableName({foo})) //returns string "foo"
console.log(getVariableName({bar})) //returns string "bar"

The only (small) catch is that you have to wrap your unknown variable between {}, which is no big deal.