Ben Robie brobie

## Javascript Variable Scoping.md

      
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                hartleybrody
                / Javascript Variable Scoping.md
            
            
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              February 3, 2019 19:13
            
              
                Variable scoping in Javascript can be confusing so I set out to make notes of the basic rules so that I can reference them later. Hope these are useful to others, happy to talk pull requests for corrections.
              
          
    Javascript has two kinds of scope:

Local (inside a function)
Global (outside a function)

The var Keyword


Using the var keywords creates the variable in the current scope

If the current scope is global, then var is unnecessary (see below)
If the current scope is local, then you’re creating a local variable in the current scope


If you don’t use var, then Javascript goes up the “scope chain” to see if it’s already been declared