How can I access an Angular class variable without using `this`?

Question

Is there any way to use access the variable MyVariable from the StartPage class without using this.? The reason I am asking is that I need to reference this in a function, and this does not work there. I know from here that I could use => {... but that won't always work for me. How can I do this?

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

@Component({
  selector: 'app-start',
  templateUrl: './start.page.html',
  styleUrls: ['./start.page.scss'],
})
export class StartPage implements OnInit {

  constructor() {}

  MyVariable = "Value";

  ngOnInit() {
   console.log(MyVariable); 
   //anyway to use MyVariable without `this.` prefix?
  }

}

`The reason I am asking is that I need to reference this in a function` <= Could you share that code? Chances are you are just not binding `this` or you could be using a lambda but you were not aware how to. — Igor, Dec 18 '18 at 19:12
Consider using `this`. Your team mates and future self will thank you. If you had trouble with a specific arrow function, please post the code for it and we can help. There should not be a case where an arrow function "doesn't work". — DeborahK, Dec 18 '18 at 19:20

score 3 · Accepted Answer · answered Dec 18 '18 at 19:13

3

I need to reference this in a function, and this does not work

I think this is because you tried to access from a callback function (subscription, setTimeout or similar) and this is not defined in the context. For having access to this as a reference of StartPage class, you must bind the reference to this to the function, for example:

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

@Component({
  selector: 'app-start',
  templateUrl: './start.page.html',
  styleUrls: ['./start.page.scss'],
})
export class StartPage implements OnInit {

  constructor() {}

  MyVariable = "Value";

  ngOnInit() {
     this.myFunction().bind(this);
  }

  myFunction(){
     // ...
     this.MyVariable = someValue
     // ...
  }

}

answered Dec 18 '18 at 19:13

Diego N.

562
3
10

Seems like that would work. But is there any other way to do this? Could I do something like `StartPage.MyVariable` ? – nachshon f Dec 18 '18 at 19:16
1

@nachshonf That syntax is how you access static variables. If you want to access an instance variable, you have to refer to an actual instance. – John Montgomery Dec 18 '18 at 19:18
@nachshonf `StartPage.MyVariable` would be something like a constant value, instead of a instance of the object itself. I can't tell if it could be done as far I know – Diego N. Dec 18 '18 at 19:19

How can I access an Angular class variable without using `this`?

1 Answers1