JavaScript scope in a try block

Question

Say I'm trying to execute this JavaScript snippet. Assume the undeclared vars and methods are declared elsewhere, above, and that something and somethingElse evaluate to boolean-true.

try {     if(something) {         var magicVar = -1;     }      if(somethingElse) {         magicFunction(magicVar);     } } catch(e) {     doSomethingWithError(e); } 

My question is: what is the scope of magicVar and is it okay to pass it into magicFunction as I've done?

Answer 1

Lots of other good answers about how Javascript handles this with var, but I thought I'd address the let situation...

If a variable is defined with let inside the try block, it will NOT be in scope inside the catch (or finally) block(s). It would need to be defined in the enclosing block.

For example, in the following code block, the console output will be "Outside":

let xyz = "Outside";  try {     let xyz = "Inside";      throw new Error("Blah"); } catch (err) {     console.log(xyz); }