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Access "variable" environment variable using dynamic javascript variable names

I have an issue. In my Host/cloud solution, I must use environment variables of pricing for each country this way 'defined in their "Environment Variables").
BASIC_PRICE_FR_PRODUCT = "50";
COMPLEX_PRICE_FR_PRODUCT = 100;
BASIC_PRICE_UK_PRODUCT = "37";
COMPLEX_PRICE_UK_PRODUCT = "200";
BASIC_PRICE_ES_PRODUCT = "75";
COMPLEX_PRICE_ES_PRODUCT = "300";
I can access those using process.env.XXX such as process.env.BASIC_PRICE_FR
As you see these environment variables depend on the country as the price vary from one country to the other.
In our node.js app, the challenge is that when a function is executed, it is self aware of the country so, we can (and must) use the "current" country and the current country_iso_code ("fr" for example), and with this we must use the pricing that match this country.
After reading on SO some posts on "dynamic variable names" , I tried eval, global[] and window[] like below, but none work and all outputs "undefined" values
//note: iso_code_3166_we_can_use is something passed to the function by the final user or by some other lambda in the function context.
const current_country_iso_code_uppercase = iso_code_3166_we_can_use;
const basicPrice = parseInt( "process.env.BASIC_PRICE_" + current_country_iso_code_uppercase + "_PRODUCT")
console.log(basicPrice)//bug here as outputs "undefined"
EDIT
The suggestion of using process.env['xxx'] did not work so I add here the results
console.log(process.env.BASIC_PRICE_FR_PRODUCT);//outputs 50
console.log('BASIC_PRICE_' + iso_code_uppercase + '_PRODUCT' );//just to be sure :): outputs BASIC_PRICE_FR_PRODUCT
console.log( process.env['BASIC_PRICE_' + iso_code_uppercase + '_PRODUCT'] );// DOES NOT WORK, outputs undefined

Use [] to dynamically access an object's property:
var country = 'FR'
var price = process.env['BASIC_PRICE_' + country + '_PRODUCT']

//Create an empty dictionary,
var process_env_dict = {};
process_env_dict['env'] = process.env;
//then you can access it with the below statement as you expected
var result = JSON.parse(JSON.stringify(process_env_dict))['env']['BASIC_PRICE_' + country + '_PRODUCT'];

Change a variable that's name is in another variable

I've got a bit of a problem here. I've got the following code declaring two variables:
var anawesomevariable = "hello world";
var variabletwo = "anawesomevariable";
As you can see, the second variable's contents are the same as the name of the first variable. My problem: I want to change the first variable using the contents of variabletwo. So in other words, I want to say "Hey Javascript, change the contents of the variable whose name is in variabletwo". Is there any way to do this in Javascript?
P.S. I havn't really explained that clearly, but you get my point (I hope)

You can do
eval(variabletwo + ' = "new value"');
which results in running the code
anawesomevariable = "new value";

If awesomevariable is a global variable you can do this:
window[variabletwo] = 'goodbye world';

You cannot* (and should not) manipulate variables, but it's a piece of cake with properties:
var obj = {anawesomevariable: "hello world"};
var variabletwo = "anawesomevariable";
obj[variabletwo] = whatever
^* don't even think about "eval" here. seriously.

You have a few options. Option 1, which uses eval(), which I discourage, would be simplest, like this
eval(variabletwo + ' = "cool"');
The second option is to declare them as globals, like this
window.anawesomevariable = "hello world";
window.variabletwo = "anawesomevariable"
and then
window[variabletwo]="foo";
However, if you want to keep something in the current scope, declare it in an object, like this
var obj = {anawesomevariable: "hello world"};
var variabletwo = "anawesomevariable";
obj[variabletwo] = "foo";

Is there a way to make a dynamic variable name based on the value of another variable?

Is there a way to make the value of a variable the name for another variable? For example, I want the variable name (value_of_i) to be what ever number "i" is during that iteration. The while loop below is not what I'm using it for, it's just to explain what I'm asking.
var i = 1;
while(i<10)
{
var value_of_i = "This loop has ran " + i + "times.";
i++;
}
For the first iteration, "i" is equal to 1 so I would want the variable name to be "1":
var 1 = "This loop has ran " + i + "times.";
And the second interation:
var 2 = "This loop has ran " + i + "times.";

Yes. Using bracket notation (Here is a tutorial in MDN)
Here is a working fiddle
When doing something like containingObject[stringVariable] you are accessing the property in containingObject whose name is the value stored in stringVariable.
// this assumes browser JavaScript where window is the global namespace
// in node.js this would be a little different
var i=0;
while(i<10){
window["counters"+i] = "This is loop has ran " + i + "times.";
i++;
}
console.log(counters3);
If you'd like you can use this instead of window, however this might fail in strict mode.
Here is the main explanation of how bracket notation works from the MDN link above:
Properties of JavaScript objects can also be accessed or set using a bracket notation. Objects are sometimes called associative arrays, since each property is associated with a string value that can be used to access it. So, for example, you could access the properties of the myCar object as follows:
myCar["make"] = "Ford";
myCar["model"] = "Mustang";
myCar["year"] = 1969;
You can also access properties by using a string value that is stored in a variable:
var propertyName = "make";
myCar[propertyName] = "Ford";
propertyName = "model";
myCar[propertyName] = "Mustang";

You can't make a variable name a number, its not a valid name. So var 1="" is invalid.
But to dynamically set the value you can do
var x = "variablenamehere";
window[x] = "variablevaluehere";
Thats the same as
var variablenamehere
except that it will be scoped as a global variable and will be accessible everywhere, rather than being limited to the current function scope.

Why not store your strings in an array that is indexed by i?
That way you can reference them later efficiently and easily;
var loopI = new Array();
for(var i = 0; i < 10; ++i) {
loopI[i] = "This loop has ran " + i + "times.";
}

This works:
var o = {};
var d = "dog";
for (var k = 0; k < 5; k += 1) {
o[d+k] = k*100;
}
console.log(o.dog3); // 300
This comes closer to doing what you want:
var N = {};
var M = {};
var i = 1;
while(i<10)
{
N[i] = "This loop ran " + i + " times.";
// Or, so you can use dot notation later:
M['OO'+i] = "This loop ran " + i + " times.";
// Those are capital O's, not zeros. Numbers won't work.
i++;
}
console.log(N[3]); // This loop ran 3 times.
console.log(M.OO7); // This loop ran 7 times.
The 'OO' notation could cause bewilderment and wasted time for others trying to use your code; but it could also be a source of amusement for them. This reminds me of a chess board after white's first two moves are to bring out a knight and then put it back. The board then seems to show that black moved first, and some people will endlessly insist that the configuration proves there was illegal play unless someone tells them what happened.

Get variable names with JavaScript

I want to create a log function where I can insert variable names like this:
var a = '123',
b = 'abc';
log([a, b]);
And the result should look like this in the console.log
a: 123
b: abc
Get the value of the variable is no problems but how do I get the variable names? The function should be generic so I can't always assume that the scope is window.

so the argument is an array of variables? then no, there is no way to get the original variable name once it is passed that way. in the receiving end, they just look like:
["123","abc"];
and nothing more
you could provide the function the names of the variables and the scope they are in, like:
function log(arr,scope){
for(var i=0;i<arr.length;i++){
console.log(arr[i]+':'scope[arr[i]]);
}
}
however, this runs into the problem if you can give the scope also. there are a lot of issues of what this is in certain areas of code:
for nonstrict functions, this is window
for strict functions, this is undefined
for constructor functions, this is the constructed object
within an object literal, this is the immediate enclosing object
so you can't rely on passing this as a scope. unless you can provide the scope, this is another dead end.
if you pass them as an object, then you can iterate through the object and its "keys" and not the original variable names. however, this is more damage than cure in this case.

I know you want to save some keystrokes. Me too. However, I usually log the variable name and values much like others here have already suggested.
console.log({a:a, b:b});
If you really prefer the format that you already illustrated, then you can do it like this:
function log(o) {
var key;
for (key in o) {
console.log(key + ":", o[key]);
}
}
var a = '1243';
var b = 'qwre';
log({
a:a,
b:b
});
Either way, you'd need to include the variable name in your logging request if you want to see it. Like Gareth said, seeing the variable names from inside the called function is not an option.

Something like this would do what you're looking for:
function log(logDict) {
for (var item in logDict) {
console.log(item + ": " + logDict[item]);
}
}
function logSomeStuff() {
var dict = {};
dict.a = "123";
dict.b = "abc";
log(dict);
}
logSomeStuff();

Don't know if this would really work in JS... but you can use a Object, in which you can store the name and the value:
function MyLogObject(name, value) {
this.name = name;
this.value = value;
}
var log = [];
log.push(new MyLogObject('a', '123'));
log.push(new MyLogObject('b', 'abc'));
for each (var item in log) {
if (item.value != undefined)
alert(item.name + "/" + item.value);
}
Then you can loop thru this Object and you can get the name and the value

You can't access the variable names using an Array. What you could do is use objects or pass the variable names as a String:
var x = 7;
var y = 8;
function logVars(arr){
for(var i = 0; i < arr.length; i++){
alert(arr[i] + " = " + window[arr[i]]);
}
}
logVars(["x","y"]);

I had a somewhat similar problem, but for different reasons.
The best solution I could find was:
MyArray = ["zero","one","two","three","four","five"];
MyArray.name="MyArray";
So if:
x=MyArray.name;
Then:
X=="MyArray"
Like I said, it suited my needs, but not sure HOW this will work for you.
I feel silly that I even needed it, but I did.

test this.
var variableA="valor01"; <br>
var variableB="valor02";
var NamevariableA=eval('("variableA")');<br>
var NamevariableB=eval('("variableB")');<br>
console.log(NamevariableA,NamevariableB);
atte.
Manuel Retamozo Arrué

Global var in JavaScript

This is annoying me.
I'm setting an array in beginning of the doc:
var idPartner;
var myar = new Array();
myar[0] = "http://example.com/"+idPartner;
And I'm getting a number over the address, which is the id of partner. Great. But I'm trying to set it without success:
$.address.change(function(event) {
idPartner = 3;
alert(idPartner);
}
Ok. The alert is giving me the right number, but isn't setting it.
What's wrong?

Changing the value of the variable does not re-set the values within the array. That is just something javascript can't do automatically. You would have to re-generate the array for it to have the new id. Could you add the id to the value where you use the array instead of pre-setting the values in the array containing the id?
Edit: For example, you would do:
var myArray = [];
var myId = 0;
myArray[0] = "http://foo.com/id/";
and when you need to use a value from the array, you would do this:
var theVal = myArray[0] + myId;

Try this:
var myvar = ["http://site.com/"];
$.address.change(function(event) {
myvar[1] = 3;
}
then use myvar.join () where you need the full url.

The problem here is that at the line
myar[0] = "http://site.com/"+idPartner;
..you perform a string concatenation, meaning you copy the resulting string into the array at index position 0.
Hence, when later setting idPartnerit won't have any effect on the previously copied string. To avoid such effect you can either always construct the string again when the idPartnervariable updates or you create an object and you evaluate it when you need it like...
var MyObject = function(){
this.idPartner = 0; //default value
};
MyObject.prototype.getUrl = function(){
return "http://site.com/" + this.idPartner;
};
In this way you could use it like
var myGlblUrlObj = new MyObject();
$.address.change(function(event){
myGlblUrlObj.idPartner = ... /setting it here
});
at some later point you can then always get the correct url using
myGlblUrlObj.getUrl();
Now obviously it depends on the complexity of your situation. Maybe the suggested array solution might work as well, although I prefer having it encapsulated somewhere in an object for better reusability.

myar[0] = "http://site.com/" + idPartner;
After this line, myar[0] = "http://site.com/undefined" and it has nothing to do with the variable idPartner no more.
So, after that changing the value of idPartner will affect the value of myar[0].
You need to change the value of myar[0] itself.