I have a class to which I would like to include a method of overriding some of the default instance variables in the constructor, without having a dozen parameters. I would like to do this by passing an object in the form of: In Python this could be done with Is there a JS equivalent or do I just have
Tag: class
How to mock a constructor instantiated class instance using jest?
Given a class Person that instantiates & uses another class Logger, how can the Logger’s method be verified to be called when Person is instantiated in the example below? One option is to pass Logger as a constructor argument like below: However, is there any other way without changing the construct…
TypeScript Argument of type ‘IAccount’ is not assignable to parameter of type ‘never’
I am getting the above error when using the following types: I am trying to initialize an account in my JSON file inside of a class constructor: I have tried to get this to work in multiple ways, I feel like I am missing something in the interface definitions. Answer You need to specify the type of accountsOb…
Why do extended classes uses prototypes for methods but not for fields?
Looking at this simple code : Result in Chrome is : As we can see, the instance methods are on the prototype (for each constructor function) Question: Why are fields, as opposed to methods, not on the prototype? I mean , someField is in Animal not in Lion. Answer This is the intended behavior as seen in ECMAS…
How can I change data-id value in Class with a script?
I need to set random data-id with two value A y B. I need a script that can do this Answer For archiving this think you have to do three steps. First: Collect all values you need into an array. Second: Generating a random integer number. Based on Generate random number between two numbers in JavaScript The pa…
How @Inject(REQUEST) works and how to destructure it
The first question is how it’s possible that an injected parameter is changing after the class initialization. Because this code works and this code doesn’t work The second example doesn’t have ‘userId’ yet that should be injected by my nest.js interceptor. Why it’s like th…
TypeScript immutable data/classes with mutual reference
Usually when I create a TypeScript application I follow an OOP + immutable data philosophy. So let’s suppose I have two classes with mutual reference, class A and class B. Now it’s impossible to create instance of class A, since class B is required in constructor to achieve immutability, and class…
How to add a class to a each li whenever you scroll to it with jquery
I have a list with many li I’d like to add a class to each li only when I scroll to that specific li The issue is the class is added to every li once I scroll to only 1 of them Thanks in Advance Answer I couldn’t find what’s wrong with your code so I made another version of
JavaScript – Confusion between global classes and inheritance
Total begginer who learns JS here. I don’t understand why when you declare a variable it doesn’t TOTALLY inherit of it’s parent class methods, for e.g.: Why don’t the variables inherit of all of the methods of it’s parent classes? Instead of that you need to mix between the fonct…
What’s ExtendedMessage on discord.js
I’m on v12 and after a lot of time I decided to start coding again but I ran into a problem I can’t quite fix. At start I wanted to add a function to the Message class like so But after a while I saw that some messages I sent did not have this function and threw me an error