What is a closure in JavaScript?

Question

Options

• AA type of event handler.
• BA function having access to the parent scope, even after the parent function has closed.
• CA method used to close a web page.
• DAn error in JavaScript code.

• A
  7% (1)
• B
  86% (12)
• D
  7% (1)

Explanation

Option B is correct because a closure is formed when a function "closes over" variables from its outer (parent) scope, retaining access to those variables even after the parent function has finished executing - this is a core feature of JavaScript's lexical scoping. Option A is wrong because event handlers are callbacks assigned to DOM events, a separate concept entirely. Option C is wrong because JavaScript has no built-in mechanism to "close" a web page programmatically in that sense. Option D is wrong because closures are intentional, well-defined behavior, not an error.

Memory tip: Think of a closure like a backpack - when an inner function leaves its parent, it carries the parent's variables with it in that backpack, using them whenever needed later.

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