Im struggling with the general mechanics of the “this” keyword… or should i say… there are only verryy isolated incidents where im actually SURE of what “this” is going to do… mdn just keeps leaving me with more questions than answers… any form of help would be greatly appreciated ** I understand i…

Heres a contextualizer Array.prototype.myMap = function(callback) { const newArray = []; for(let i = 0 ; i < callback.length ; i += 1){ let item = callback[i]; newArray.push(item) } return newArray; };```

It’s whatever object is to the left of the dot when a function is called, ie the context. [image] Functional Programming - Implement the filter Method on a Prototype JavaScript When you call your function, this is what is to the left of the dot. [1, 1, 2, 5, 2].myFilter(…

so… implementing “this” into the above snippet… to mimic prototype.map ???

suggestions before answers please :innocent: :innocent:

it feels like im replacing callback with “this”

Well in that particular case it’s attaching a function to the Array object that mimics the built-in filter function, not the built-in map function. That’s not super important, it was just an example, the person was also asking what this is. Everything you can call functions on is an object in JS. E…

[image] freeCodeCamp.org Learn to Code — For Free

i understood the assignment to be including the implementation of “this” to mimic array.map

[image] Ian.M: it feels like im replacing callback with “this” No. this solves the problem of “I have an object. It has a function attached to it. How do I refer to that actual exact object the function lives in from inside that function”

Ah I was talking about what I posted, the link to an explanation of this

Trying to get a better grasp of "this" keyword

Programming JavaScript

Ian.M March 25, 2023, 6:59pm 8

Topic		Replies	Views
Use of this on "Implement map on a Prototype" exercise JavaScript	5	385	February 18, 2022
Question of "this" at implement map JavaScript	7	463	March 7, 2022
The This Keyword-(Implement the filter Method on a Prototype) JavaScript	4	535	January 25, 2021
Implement map on a Prototype: detailed description JavaScript	10	4247	December 24, 2020
Functional Programming - Implement map on a Prototype JavaScript	8	426	September 24, 2023

Trying to get a better grasp of "this" keyword

Related topics