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Arrow function

giandodev profile image GiandoDev ・1 min read

Arrow function is a syntactic sugar which ES6 brings us.
Here an example of a simple arrow function:
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If we have just one parameter in our function we may write our arrow function in two ways:
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Maybe we don't have any parameter and we have still two options:
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Arrow function provide, by default, an implicit return statement if two condition are present:
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markdown guide

This is a great and easy way to explain switching from the old way of defining functions to using arrow functions.


Why need arrow function?
Is it comes with just short our code or ........what?


Arrow functions do not have a arguments array

In JS arguments array in functions is a special object that can be used to get all the arguments passed to the function. Similar to this, arrow functions do not have their own binding to a arguments object, they are bound to arguments of enclosing scope.

Arrow functions are callable but not constructable

If a function is constructable, it can be called with new, i.e. new User(). If a function is callable, it can be called without new (i.e. normal function call).

Functions created through function declarations / expressions are both constructable and callable.

Arrow functions (and methods) are only callable. class constructors are only constructable.

If you are trying to call a non-callable function or to construct a non-constructable function, you will get a runtime error

let arrowFunc = () => {}
new arrowFunc()
This code gives the error:
arrowFunc is not a constructor



Not really. Arrow functions don't have their own this, which can be handy in some cases.


I don’t want to sell you my point of view, instead I suggest you read what they say here and get your own idea based on your style of writing code.