Should I unsubscribe from Cold Observable?

Question

I know that it\'s good practice to unsubscribe from Observable to prevent memory leak.

But if it\'s Cold Observable

Answer 1

It is definitely the best practice to free the used memory in javascript just like other programming languages.

Since you are using angular 2 you can use ngOnDestroy life cycle hook to achieve as this method is executed when the component loses its scope.

Assuming that you use a below snippet to subscribe to a data

subscription = this._http.getMethod('...')
                    .subscribe(response => this.responses = response,
                    error =>this.errorMessage = error)

You should be using importing OnDestroy lifecycle hook from angular/core using an import statement.

import { OnDestroy } from '@angular/core'

implement OnDestroy in your component as

export class MyComponent implements onDestroy {
     .............


     ngOnDestroy() {
          this.subscription.unsubscribe();
     }

}