Error encountered while injecting Angular dependencies in component constructor

Here is my newly created component. I am looking to allow users to adjust the count variable.

import { Component, Inject } from '@angular/core';

@Component({
  selector: 'app-likebtn',
  templateUrl: './likebtn.component.html',
  styleUrls: ['./likebtn.component.css']
})
export class LikebtnComponent {
  selected: boolean = false
  count: number = 0

  constructor(count: number) {
    this.count = count;
  }

  handleClick() {
    this.selected = !this.selected
    if(this.selected)
      this.count++
    else
      this.count--
  }
}

I have followed various tutorials and guides online, but I keep encountering errors such as the ones shown in this image: https://i.stack.imgur.com/MmqxE.png

Please assist me!

I have attempted using @Inject notation, recreating the component, and more without success. All I want is to include a constructor in my component.

Answer №1

Angular's dependency injection system is specifically designed to handle the injection of services rather than primitive values like numbers. If you would like users to be able to adjust the count variable, it is advisable to create an @Input() property for the count value.

import { Component, Input } from '@angular/core';

@Component({
  selector: 'app-likebtn',
  templateUrl: './likebtn.component.html',
  styleUrls: ['./likebtn.component.css']
})
export class LikebtnComponent {
  @Input() count: number = 0;
  selected: boolean = false;

  handleClick() {
    this.selected = !this.selected;
    if (this.selected) {
      this.count++;
    } else {
      this.count--;
    }
  }
}

Answer №2

There is no requirement to pass the count through the constructor. You have the option to eliminate the constructor altogether.

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