Application constants

Hello another newbie question.
Is there a way to set a variable at the application scope. Like a constant in Java. Basically something like:
storeID = “usedOnEveryPage”;

Then in each .ts file we can reference storeID when needed. Something like app.storeID as opposed to this.storeID where it would be defined in each .ts file. Which is a maintainability nightmare. If I need to change the value of storeID then I need to change it in every page.

Is there anything like this in ionic/angular 2?

Check this tutorial out.