Higher-Order Functions in JavaScript

kamesh sethupathi

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Nov 6, 2021

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• In javascript functional programming is powered by Higher-Order Functions.

• A function that takes another function as its argument or returns a function is called a higher-order function
• Let's assume, we are given an array of radius and we have to find its area, circumference, and diameter.

General implementation

• The above code is absolutely correct, it satisfies our requirements.
• But, there is a problem with it. We are repeating ourselves a lot. Other than the core logic there is no difference in the code.
• It violates the concept of DRY ( Don’t repeat yourself)

Higher-order implementation

• Now our code looks much cleaner and it becomes easy to add custom logic in the future.
• Here the function calculate takes a callback logic function to perform the intended action.

JavaScript inbuilt functional support

• If you look into the above code, the calculate function is pretty much doing the same thing what Array.map does.
• You could see most of the JavaScript methods take a callback function, it's the core of functional programming.