Guide for generating a prototype string within a class in TypeScript

Is there a way to have a string field in a class shared among all instances instead of creating a new instance for each one?

class A { 
    a = 'hello'
    b() { return this.a;}
}
// This code snippet transpiles into an assignment in the constructor
var A = (function () {
    function A() {
        this.a = 'hello';
    }
    A.prototype.b = function () { return this.a; };
    return A;
}());
// Is it possible to place the string on the prototype like functions?
// Avoid creating multiple instances of the string
var A = (function () {
    function A() {}
    A.prototype.b = function () { return this.a; };
    A.prototype.a = 'hello';
    return A;
}());

Answer №1

Absolutely, it is indeed achievable and may be simpler than you had initially thought...

class A {
  public foo: string;
}
A.prototype.foo = 'shared among instances';

If you're curious as to why there isn't a specific keyword for defining a 'prototype member' within the class declaration, you can delve deeper into the topic here. Pay attention to the insight provided by ahejlsberg (Anders Hejlsberg).

You could also opt to declare the variable as static, in which case it would be stored within the constructor function\class itself.

Similar questions

If you have not found the answer to your question or you are interested in this topic, then look at other similar questions below or use the search

Guide to recursively iterating through an array of objects in TypeScript/Javascript

In my current programming challenge, I am dealing with an array of objects that have two properties: target and source. Additionally, there is a designated starting source to begin with. The goal is to start from the starting source and recursively find a ...

Clicking on an icon to initiate rotation (Material UI)

Is there a way to toggle the rotation of an icon (IconButton) based on the visibility of a Collapse component? I want it to point down when the Collapse is hidden and up when it's shown. const [expanded, setExpanded] = useState<boolean>(false); ...

What is the process of transforming two forms into components and then integrating those components into a view in Angular 5?

Currently, I have two forms running smoothly on the same component as shown in InfoAndQualificationComponent.ts import { Component, OnInit } from '@angular/core'; import { FormGroup, FormControl } from "@angular/forms"; @Component({ selector: ...

Executing a series of HTTP requests sequentially using Angular 5

I need some guidance on sending an array of HTTP requests in sequential order within my application. Here are the details: Application Entities : Location - an entity with attributes: FanZone fanZone, and List<LocationAdministrator> locationAdmins ...

Incorporating dynamic dictionary fields in Reactive and pushing them into an established FormControl

I am attempting to dynamically populate my reactive form with varying fields based on user selection. Here is an example of the fields I have: fields = [{ df_id: 48, df_name: "Phone Number", df_type: "text", ...

Does an AsyncMethod().Result equivalent exist in typescript?

When working in C#, you have the ability to call the result of an asynchronous method synchronously by accessing the Result property. For example: var returnVal = AsyncMethod().Result; What is a similar approach in typescript? ...

Executing multiple instances of the cascading dropdown fill method in Angular 7

I am currently working on an Angular app that includes cascading comboboxes for country and state selection. However, I have noticed that the get states() method in my state.component.ts file is taking a long time to run. What could be causing this issue? ...

Implementing setState callback in TypeScript with React Hooks

Hello everyone! I am currently working on defining my component types using TypeScript, and I am faced with a challenge. I am trying to set it up so that I can either pass an array of objects or a callback function containing the previous state. Below is t ...

Is there a way to retrieve the timezone based on a province or state in TypeScript on the frontend?

I've been working on an angular app that allows users to select a country and state/province. My current challenge is determining the timezone based on the selected state/province, with a focus on Canada and the US for now (expanding to other countrie ...

Why do callbacks in Typescript fail to compile when their arguments don't match?

In my current project, I encountered a scenario where a React callback led to a contrived example. interface A { a: string b: string } interface B { a: string b: string c: string } function foo(fn: (a: A) => void, a: A) { fn( ...

What does ngModel look like without the use of square brackets and parenthesis?

Can you explain the usage of ngModel without brackets and parentheses in Angular? <input name="name" ngModel> I am familiar with [ngModel] for one-way binding and [(ngModel)] for two-way binding, but I am unsure what it means when ngModel ...

Optimizing row performance for Angular grids in the Chrome browser

When creating a component that includes a table with numerous rows, everything works well with small amounts of data. However, once the item count reaches 2000 or more, it starts lagging. Scrolling and animations become sluggish. Even after trying to impl ...

Retrieve data upon component mounting and deactivate the query in React-query

When navigating to a search result page, query parameters are passed to useQuery. I want the data to be fetched only when the user clicks the "Search" button after changing the search prompt. I attempted to use enabled: false and call refetch() on button ...

Deriving values in Typescript based on a subset of a union for conditional typing

Can someone provide assistance with type inference in TypeScript to narrow a union based on a conditional type? Our API validates a set of parameters by normalizing all values for easier processing. One parameter can be either an array of strings or an ar ...

Steps to globally modify the font in Ionic

In my Ionic app running version 3.9.2, I am attempting to customize the default font to a specific custom one. After researching, I discovered that I need to set the font face in the app.scss file located within the app folder. Here is the code snippet I ...

What is the best way to implement filter functionality for individual columns in an Angular material table using ngFor?

I am using ngFor to populate my column names and corresponding data in Angular. How can I implement a separate filter row for each column in an Angular Material table? This filter row should appear below the header row, which displays the different column ...

Tips for sending user IDs through an Angular 8 interceptor

Alright, In my Angular application that is using version 8, I have an HttpMaintenanceInterceptor configured without the use of cookies. Instead, I have a getAccessToken method within the authService as shown below: getAccessToken(): string { return ...

What is the best way to seamlessly update a Redux state array in an immutable manner using Typescript?

I'm embarking on a journey to grasp Typescript through the creation of a simple Todo-List application. However, I've hit a roadblock in updating the Redux state array within a slice that I've established (or rather, I'm unsure how to go ...

Displaying a list in Angular view using various object properties

A JSON object has been provided to me with the following structure: header: { first: { title: { name: "Test } }, second: { title: { name: "Test 2" }, ...

Why do I keep encountering the error "global is not defined" when using Angular with amazon-cognito-identity-js?

To start, run these commands in the command line: ng new sandbox cd .\sandbox\ ng serve Now, navigate to http://localhost:4200/. The application should be up and running. npm install --save amazon-cognito-identity-js In the file \src&bso ...