What is lexical scoping and how does it differ in various programming languages?

What is lexical scoping and how does it work in programming languages?

Lexical scoping is a rule that determines how variable names are resolved in nested functions. In languages like JavaScript, a function's scope is defined by its location within the source code.

Can you explain how lexical scoping differs in Python?

In Python, lexical scoping also applies, meaning that a function can access variables from its enclosing scope. However, Python uses a different mechanism called the LEGB rule (Local, Enclosing, Global, Built-in) to resolve names.

What about languages like Ruby or Java?

Ruby follows lexical scoping as well, allowing inner functions to access variables from outer scopes. Java, on the other hand, uses block scoping with the introduction of lambda expressions in Java 8, which allows for more flexible variable access.

Are there any languages that don't use lexical scoping?

Yes, some languages, like older versions of BASIC, use dynamic scoping instead, where the variable resolution depends on the call stack rather than the code structure.