This lesson and quiz: https://www.freecodecamp.org/learn/full-stack-developer/lecture-working-with-higher-order-functions-and-callbacks/what-is-method-chaining-and-how-does-it-work In the lesson it says: “Each method returns a new string, which becomes the target of the next method call.” Then …

Well, the transcript does say: Method chaining is a programming technique that allows you to call multiple methods on the same object in a single line of code. And this concept is reinforced in the example that chains filter(), map(), and reduce() to a transactions array (the same object). But …

The context for the second question, is in the third question. That is what is meant by “what should a method typically return”. But yes, in the context of immutable array methods, it would be a copy that is returned. But then, not all array methods are immutable, which is why we now have to versio…

I think it’s meant that each method is called in turn on the results of the previous process. If they were each called on the original array, it would reset each time and wouldn’t be chained. const totalCreditWithBonus = transactions .filter((transaction) => transaction.type === "credit") .map(…

[image] lasjorg: The context for the second question, is in the third question. Thanks that does shed a bit more light… is this how chained functions work internally? Do they typically return this ? It seems like this is not how filter, map and reduce work? They all seem to return a new obje…

In the context of method chaining, Even this is a little curious. Do the methods behave any differently when they are chained vs. if they are used standalone?

[image] pkdvalis: If they were each called on the original array, it would reset each time and wouldn’t be chained. that depends if the method is mutating or not. if the method is mutating and it returns the original array (example, sort), then it is still the original array but mutated arr.…

I would say the method needs to return a result in order to be chained. All of these methods return the result of the process whether it’s this, a new object or value. Contrast with forEach() which returns undefined and so you cannot chain a method after it. Even the example in question 3, getValu…

I would say so, but at the same time, some type of values don’t have methods to chain, or they have only toString(), consider numbers, for example, or booleans. [image] pkdvalis: A single value. there isn’t a way to return a different number of values, I don’t think this can go as correct an…

You mean something like reduce() would not allow further methods to be chained after? The methods in question 3 of the quiz are all mutative, like sort(), correct? let obj = { value: 1, increment: function() { this.value++; return this; }, double: function() { …

[image] pkdvalis: You mean something like reduce() would not allow further methods to be chained after? it depends by what is returned, if it returns a data type on which some methods can be used, than one of those methods can be chained [image] pkdvalis: The methods in question 3 of the…

What Is Method Chaining, and How Does It Work?

JavaScript

pkdvalis April 13, 2025, 3:57pm 12

So this really doesn’t have anything to do with chaining. It’s just whether or not a method returns an object which has methods that you can use for further chaining.

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What Is Method Chaining, and How Does It Work?

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