Call back function_Single Threaded_forEach

April/14/2026

Call back function

A callback function is a function pass is go another function in agrument is excuted leter.

1. A function can accept another functiona as a pass.
2. Callback allow one function to call another at later time.
3. A callback can excuted afer another function has finished.

Here, name()is passed a callback to name1(),which excutes after the name.

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Single Threaded

JavaScript run in single thread.

It can only exceute one task event task.
Multi task in one program there are one by one run speed.
A issues sometime support have a task is a time consuming.
One block run start next one.

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forEach

This is a array method only used array.
A javaScript array forEach is built in method used excuted of provided funcion one for a element in a array

normal function:

Arrow Function:

Here, automatically create value, index, array in forEach method.
What are we want used there value any one or three so.

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