Scope is fascinating (and sometimes confounding) in JavaScript.

Because debugging mysteries are often rooted in the ambiguity of scope, it is best to get a good understanding of it early.


Scope can be defined spacially as the reach of a variable.

How available/global or privileged/private is it?

Where/when is a key to... ...


Scope can also be seen as the lineage of an object.

Prototype chains are like family trees.

What does it come from...

Ad blocker interference detected!

Wikia is a free-to-use site that makes money from advertising. We have a modified experience for viewers using ad blockers

Wikia is not accessible if you’ve made further modifications. Remove the custom ad blocker rule(s) and the page will load as expected.