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Discussion on: Regular vs Arrow Function

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Isaac Lyman

Note that => is written with an equal sign and a greater-than sign, both common programming symbols and pretty accessibly on a standard keyboard.

As for why, the top reasons I use arrow functions are:
1) Succinctness. If I'm trying to add 1 to each element in listOfNumbers, the old way to do it was:

var incrementedNumbers = (num) { return num + 1; }); 
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With an arrow function I can do

var incrementedNumbers = => num + 1);
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Which is quicker to write and quicker to read.

2) Lexical context. When you write function, it creates its own this binding (that is, inside of a classic function, the this keyword refers to the function itself). But for arrow functions, this refers to the same thing both inside and outside the function; arrow functions don't create a lexical context. This is occasionally handy when I have some data in this that I need to use throughout a function, including in various predicates (like in functions passed to or async callbacks).