It removes existing data element and/or adds a new item to the array. So, the next function we’ll gonna look at is the splice function.

To have the ability to take that portion array.slice can work with two arguments (see the Difference #3). It returns a shallow copy of a portion of an array into a new array. Array.slice and array.splice are those two frequently used methods that will be required to access and change data inside those arrays.įirst let’s take a look at slice method. For example, images for galleries, banners, temporary user data, etc. JavaScript arrays are frequently used to store different types of data. Yes, you may think that there are already libraries such as ImmutableJS or Immutability Helper that solve this problem but we are in favour of using Vanilla javascript whenever possible instead of resorting to third party libraries in order not to overload the dependencies too much and so practice a little with basic Javascript, which is never too much.We’ve decided to take a “programming” topic for a change and fill in some blank places in JavaScript development topic Specifically we’ll describe Array Splice and Slice methods, how you can use this stuff, and what the difference between them.

Remember that an immutable function is one that does not modify the value on which we are applying it.įor example, splice is a mutable function because it modifies the original array, while slice returns a new array. This has led us to study concepts such as pure functions and immutability (both primary basis for libraries like Redux) and try to put them into practice whenever we can.Īlso, of course, we have had to face bugs for having used a mutable function within a reducer without realizing it, therefore, we have decided to compile all the immutable functions that we can use when working with arrays in Javascript.

In these years, we have been playing with React, which has allowed us to deeply explore Javascript and concepts such as functional programming.

Slice splice javascript