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Tag: lexical-scope

What is the lexical environment inside a callback function?

I keep hearing that arrow functions inherit the value of this from their Lexical Environment. Consider this example: Why is the value of this inside the arrow callback functions undefined (or in non-strict mode: window)? If the callback function is using the value of this from its lexical environment, shouldn’t the lexical environment be addEventListener? Answer When you call a

What is lexical scope?

What is a brief introduction to lexical scoping? Answer I understand them through examples. 🙂 First, lexical scope (also called static scope), in C-like syntax: Every inner level can access its outer levels. There is another way, called dynamic scope used by the first implementation of Lisp, again in a C-like syntax: Here fun can either access x in dummy1