Json manipulation TypeScript Angular 2

Question

I come from a Python Background and recently started programming using TypeScript and Angular2. I want to know how to obtain keys from a JSON object using TypeScript. I have a response like so:

response.text()

I pass this object to a function

removeMetaData (my_data: string){
    //(Various manipulation)...etc
}

i have read that I can call a json() method instead of text() . If I do that, what is the type I should use for my_data ?

Then, If my JSON looks like this:

{
    "count": 100,
    "next_page": "http://www.test.com/users/?page=2", 
    "prev_page": "http://www.test.com/users/?page=3", 
     "results":[
     {
          "username": "johnny"
     },
     Etc....

     ]

How do I parse that? I've read I might have to use an interface but I don't understand how.

In python it's just response["next_page"] to get the key of a dictionary, then I can assign that value to a variable within the class. That is exactly what I'm trying to achieve within a component.

Thank you.

ADDITION

list() {
    this.requestService.get(this.api_path)
    .subscribe(
    response => this.populate(response.json()),
    error => this.response = error.text()
    )

}

populate(payload: object) {
    this.count = payload.count;
    this.next = payload.next;
    this.previous = payload.previous;
   *payload.results => this.users = payload.results;******
}

Answer 1

Declare an interface which will be used as value object.

export interface IPage
{
 count:number;
next_page:string;
prev_page:string;
results:Array<any>;
...
...
}

var my_data:IPage;

Now assign parsed json value to my_data and access all the properties with '.' operator ie my_data.count, my_data.results .

Feel free to throw any question.

Answer 2

If I do that, what is the type I should use for my_data?

Its just a javascript object.

As an example if you json looks like:

{
  "foo": {
   "bar": "bas"
  }
}

Then in the parsed json (in variable someObj ) the value someObj.foo.bar would be bas 🌹