Callback using arrow function

Using arrow function as callback function can reduce lines of code.

The default syntax for arrow function is

() => {}

This can be used as callbacks

For example if we want to print all elements in an array [1,2,3,4,5]

without arrow function, the code will look like this

[1,2,3,4,5].forEach(function(x) {
     console.log(x);
}

With arrow function, it can be reduced to

[1,2,3,4,5].forEach(x => console.log(x));

Here the callback function function(x){console.log(x)} is reduced to x=>console.log(x)