Top method for declaring and setting up variables in Angular 2

I've been diving into the Angular Style Guide, but a question has come up: what is the most effective method for initializing a variable in a component?

For instance, should I declare a variable like so:

export class MyComponent implements OnInit {

  myModel: MyModel= new MyModel();

  //...
}

Or perhaps like this:

export class MyComponent implements OnInit {

  myModel = new MyModel();

  //...
}

Or maybe like this:

export class MyComponent implements OnInit {

  myModel: MyModel;

  constructor() {
    this.myModel = new MyModel();
  }

  //...
}

Is there another optimal approach that I should be aware of? You can find the Style Guide that I've been referencing here.

Answer №1

The initial method is unnecessary because the variable type has already been specified when using

"name" : type = new objectType();
. The second method is preferable since it specifically states that there is a PUBLIC variable in the class. The third method is also good, but keep in mind that it binds the variable to an instance of the class.

Personally, I always opt for the second method. If you use Visual Studio Code as your TextEditor, consider downloading the TSlint plugin for assistance with syntax!

I hope this information is useful for you.

Answer №2

In my opinion, the second option may not be considered "accurate" as it lacks type information. This could potentially result in assigning a completely different type to the variable at a later stage.

As for the other two choices, it ultimately boils down to personal preference as there is no definitive style guide to follow.

I tend to opt for the first option when I want the variable to have a default assignment or when I want to restrict any changes to it (adding a readonly flag is also an option in this case).

The third option is my go-to for all other scenarios. This is particularly useful when it doesn't matter if the variable is initialized or when there is a likelihood of the model reference changing multiple times.

Given the example you provided where the value is set in the constructor, I would personally go with the first option.

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

After saving any HTML, SCSS, or TS file, Angular 12 does not compile immediately

Recently I upgraded my Angular project from version 8 to 12 and then migrated to eslint. However, I have encountered an issue where the compilation does not begin immediately after saving a file. There is a delay of approximately 2 minutes before the compi ...

How to remove the footer on a particular webpage

I am currently using angular version 14. On a specific page, there is a footer visible that I wish to hide. This page pertains to job search, and I would like to remove or conceal the footer specifically from this job search page. The footer has been separ ...

Angular: Modules that are lazily loaded are only loaded into memory and executed, but

I am facing an issue with lazy loading in my Angular application. I have an AppModule that lazily loads MainModule, which in turn lazy loads HomeModule. The problem is that while MainModule loads fine, HomeModule gets loaded but is not rendered inside the ...

What is the reasoning behind Angular's ViewEncapsulation enum having keys with no associated value of 1

While reviewing the source code of the angular viewEncapsulation, I came across an enum that had three options but no element with a value of 1. Why are there three options without an element corresponding to 1? https://i.sstatic.net/A4lyh.png ...

Develop StoryShots for integrating with Angular in the Storybook framework

I am currently working on an Angular v8 application integrated with Storybook. My goal is to incorporate automated visual testing using StoryShots. After following the instructions detailed in this guide, I made necessary adjustments in the Jest configurat ...

Issue encountered while attempting to differentiate 'object Object'. NgFor only permits arrays and iterables

Having a JSON file containing a list of properties for sale, I am attempting to utilize *NgFor to iterate through the data and generate a list. Being relatively new to Angular and app development, there's a possibility that I might have misunderstood ...

Angular: Exploring the Dynamic Loading of a Component from a String Declaration

Is there a way to compile a component defined by a string and have it render in a template while still being able to bind the click event handler? I attempted to use DomSanitizer: this.sanitizer.bypassSecurityTrustHtml(parsedLinksString); However, this a ...

Building basic objects in TypeScript

My current project involves utilizing an interface for vehicles. export interface Vehicle { IdNumber: number; isNew: boolean; contact: { firstName: string; lastName: string; cellPhoneNumber: number; ...

Can't decide between ngOnInit() and ngAfterContentInit()?

As a newcomer to Angular, I sometimes get confused about the ngOnInit() and ngAfterContentInit() lifecycle hooks. According to the official documentation: ngOnInit() : This hook is used to initialize the directive/component after Angular has displayed the ...

What is the method for extracting individual elements from an object returned by a React hook in Typescript?

I am currently working on a component that needs access to the query parameters from React Router. To achieve this, I have been using the use-react-router hook package in my project. This is what I am trying to accomplish: import React from "react; impor ...

Issue with auto formatting quotes in IntelliJ / WebStorm is no longer functioning as expected

Currently, my TSLint configuration is set to permit the use of single quotes (') instead of double ones ("). Previously, I was able to conveniently switch all instances of " to ' in a file by using the Reformat Code shortcut CTRL + ALT ...

Scroll to top in Angular 2 after the page finishes loading

While fetching data, I have added a loading feature. My view list includes pagination and page size. The issue arises when I change the page size and move to other pages immediately after loading, as it does not scroll back to the top. I have tried adding ...

When updating data with Angular Reactive Forms, the default value of input appears as 'undefined' upon submission, even though it is bound to the value property rather than the placeholder

I have developed a versatile Angular component that I am using to create various forms for the purpose of easily modifying multiple data items. Within this component, I have incorporated 2 input fields which are tied to input properties while iterating ov ...

When additional lines are drawn elsewhere on the HTML5 Canvas, the diagonal lines will gradually appear thicker and more pronounced

For horizontal and vertical lines, using a translation of 0.5 for odd stroke widths results in crisper and sharper lines. But what about diagonal lines? Link to jsfiddle <!DOCTYPE html> <html lang="en"> <body style="background: black"& ...

What is the best way to import a data type from another file into a `.d.ts` file without converting it into a module?

Recently encountered a peculiar scenario involving d.ts files and namespaces. I have some d.ts files where I define and merge a namespace called PROJECT. Take a look at how it's declared and automatically merged (across multiple files) below: file1 ...

The module "angular2-multiselect-dropdown" is experiencing a metadata version mismatch error

Recently, I updated the node module angular2-multiselect-dropdown from version v3.2.1 to v4.0.0. However, when running the angular build command, I encountered an "ERROR in Metadata version mismatch for module". Just to provide some context, I am using yar ...

A mistake was made: The template contains errors stating that 'app-my-profile' is an unknown element

I encountered an error message: "Uncaught Error: Template parse errors: 'app-my-profile' is not a known element," while working on setting up my profile service. import { BrowserModule } from '@angular/platform-browser'; import { NgM ...

Securing Credit Card Numbers with Masked Input in Ionic 3

After testing out 3-4 npm modules, I encountered issues with each one when trying to mask my ion-input for Credit Card numbers into groups of 4. Every module had its own errors that prevented me from achieving the desired masking result. I am looking for ...

What is the process for creating an Angular library using "npm pack" within a Java/Spring Boot application?

In my angular project, we have 5 custom libraries tailored to our needs. Using the com.github.eirslett maven plugin in our spring boot application, we build these libraries through the pom.xml file and then copy them to the dist/ folder. However, we also ...

Leveraging Material UI and TypeScript for Effective Styling: Maximizing the Use of !

Currently, I am in the process of developing a React application and incorporating Material UI for my components. One query that has arisen is regarding how to apply an !important property to a style. My attempt at achieving this looked like: <Paper cl ...