Error when trying to inject a service into an angular component “EXCEPTION: Can't resolve all parameters for component”, why?

Question

I\'ve built a basic app in Angular, but I have encountered a strange issue where I cannot inject a service into one of my components. It injects fine into any of the three o

Answer 1

In my case, it happened because I didn't declare the type for a constructor parameter.

I had something like this:

constructor(private URL, private http: Http) { }

and then changing it to the code below solved my problem.

constructor(private URL : string, private http: Http) {}