Javascript: Reference a variable name from the variable itself

Question

I want to create a quick function that will console.log a variable name and the value. I'd like the result of the function to show in the console: foo: bar.

My basic idea for the function looks like this:

function varlog(var_name) {     console.log(var_name + ": " + eval(var_name)); } 

And I'd call is thusly:

function someRandomFunction() {     var foo = "bar";     // ... some stuff happens     varlog("foo"); } 

This works if foo is global, but doesn't work in the example provided. Another option that also only works globally is using window[var_name] instead of the scary eval.

I don't think what I'm asking is possible, but I figured I'd throw it out there.

I'm spending a lot of time attempting to be lazy. My current method is just console.log('foo: ' + bar); which works just fine. But now I just want to know if this is possible.

Some other questions I referenced in searching for this / creating what I have now:

• Variable name as a string in Javascript
• How to convert variable name to string in JavaScript?
• Javascript, refer to a variable using a string containing its name?
• How to find JavaScript variable by its name

--

Edit: I'd love to just call varlog(foo), if the name "foo" can be derived from the variable.

Answer 1

Solution - (for your actual use case) - console.log({foo})

In ES6 IdentifierReferences are being accepted as PropertyDefinitions on the ObjectLiteral's PropertyDefinitionList (see compatibility chart):

The variable name is being set to the Object's Property's key
and the variable value is being set to the Object's Property's value.

As console.log shows Objects with their Propertiy/ies' keys and values you can use that to see both your variable's name and value by invoking console.log({foo}).

Note that when you initialize a single anonymous object with several variables as I did in the second console.log while they appear in the same order as initialized here in the snippet's output they might get reordered (alphabetically) elsewhere.

var testint = 3  var teststring = "hi"  var testarr = ["one", 2, (function three(){})]  var testobj = {4:"four", 5:"five", nested:{6:"six",7:"seven"}}  console.log({testint})  console.log({testint, teststring, testarr, testobj})

Answer - (to the question title) - Object.keys({foo})[0]

You can also use this shorthand Object Initializer together with Object.keys() to straightly access the variable name:

var name = "value"  console.log(Object.keys({name})[0])