forEach() in JavaScript

Concise explanation of forEach() method in Js

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1. Iterates through an array.
2. Runs a callback function on each value in the array.
3. Returns undefined.

Note: forEach always returns undefined.

How does it work?

Parameters:

• Callback Function: Function to execute on each element. It is called with the following arguments:
• Value: Current element being processed in the array.
• Index: index of the element in the array.
• Array: The complete array on which forEach method is called.
• thisArg: Value to use as this when executing the callback function.

Note: In the callback function we don’t always have to use the three parameters (Value, Index, Array), Use whichever ones you need, just remember the order is important.

Note: thisArg parameter is optional too.

Examples:

1. Given an array, print all the values in the console using forEach().

2. Return the sum of all elements in the array using forEach().