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Muhammad Hamza Hijazi
Muhammad Hamza Hijazi

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Javascript callback functions are by default Synchronous or Asynchronous ?

Many times we pass callback functions to perform different tasks. In node.js these callback functions halp us to work Asynchronously but do they have the same impact in vanilla is code or anywhere else we use Javascript ?

Discussion (2)

robvirtuoso profile image

In the browser, callbacks are mostly synchronous with the exception of:

  • event handlers
  • request-response handlers
  • timer callbacks (setTimeout, clearTimeout)

But even in Node.js you have many synchronous callbacks, which you may not know as "callbacks". In particular, callbacks for iterating arrays, i.e. forEach, map, reduce.

hijazi313 profile image
Muhammad Hamza Hijazi Author

Thanks buddy