Scope Is Mine 2: The Sequel

Chapter 2: Variable Scope, Variable Problems

Wherein our hero, Debugging Dave, learns about the perils of nested scopes.

Example Time!

      
        // Example of variable scope in action
        var x = 5;
        {
          var x = 10;
          console.log(x); // Output: 10
        }
        console.log(x); // Output: 5

Don't forget, scope is like a big ol' box that contains your variables. If you try to access something outside the box, you'll get a "ReferenceError".

Scope Gotchas to Watch Out For

Global scope: where all the variables go to get all up in your face.
Local scope: where variables are just chillin', not gettin' too big for their britches.
Lexical scope: where variables are just tryin' to get some R&D done.

Scope Scope Scope! It's like a never-ending puzzle!

And don't even get us started on block scope...