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JavaScript

Posted by William Warme
William Warme
43 Points

Basic JavaScript Questions

Please add your answers : -

Q1. How many types of scopes are there in JavaScript?

Q2. Explain closure?

Q3. Is let and const are the var replacement?

1 Answer

Steven Parker
Steven Parker
243,656 Points
Steven Parker
Steven Parker
243,656 Points
  1. "Function" scope includes the code inside a function, "block" scope includes the code between braces, and "global" scope is the entire program.
  2. A "closure" is the scope of a function defined within another function. It has access to the variables defined in the outer function, but it has variables and/or functions of its own which are private.
  3. "Let", "const" and "var" are all declaration keywords, with slight differences. "Var" has function scope, while "let" and "const" have block scope. And "const" additionally prevents any changes after initialization. The purpose of a variable will determine which declaration is the most appropriate for it.
William Warme
William Warme
43 Points

Steven Parker, As I know there is only one type of scope in JavaScript which is lexical scope and block, function and global scope are the part of it. If I'm wrong let me know.

Steven Parker
Steven Parker
243,656 Points
Steven Parker
Steven Parker
243,656 Points

Perhaps I misunderstood what you meant by "type". Yes, JavaScript has only lexical (or "static") scope.