Read and edit global javascript variable from Angular

Issue

I have an angular app where in my index.html i have a variable inside a tag, like this:

<script type="text/javascript">
let global = 5;
</script>

I need to read and edit the value of this variable, inside an angular component, but I do not know how to do it.

I saw that it is possible to read the value if you create the variable inside the "window" object of javascript (window.global = 5) and then use it in angular component, but i think it would not work for me because i need that variable to be outside, as specified above.

Is it possible? Any ideas?

Solution

The keyword declare to the rescue: first, declare your global with var (let doesn't work)

<script type="text/javascript">
  var someVar = 5;
</script>

and access it in, say, Angular component:

declare var someVar;
// ...
    this.foo = someVar;

https://stackblitz.com/edit/angular-ivy-zjpnzq?file=src%2Fapp%2Fhello.component.ts

Answered By - mbojko