Doubts with Object declaration and accessing properties in TypeScript

Asked Sep 17 '17 at 08:48

Active Sep 17 '17 at 09:13

Viewed 36 times

If I send an object like this:

this.someProvider.someFunction({data: myData});

I need to access it with:

someFunction(something: Object) {
    console.log(something['data']);  // myData
    console.log(something.data)      // 'Property data does not exist on type Object'
}

But if I declare the object:

var object = {};
object['data'] = myData;

this.someProvider.someFunction(object);

I can access it like:

someFunction(something: Object) {
    console.log(something.data)      // myData
    console.log(something['data']);  // myData
}

Why? What is the difference between these two ways of declaring and accessing the properties of an object?

edited Sep 17 '17 at 09:13

asked Sep 17 '17 at 08:48

Ivan Lencina

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what error do you get? – Nina Scholz Sep 17 '17 at 08:49
You need to show us how you get to `this` – mplungjan Sep 17 '17 at 08:50
You've tagged this [tag:typescript]; are you actually using TS? By *"It doesn't works"* do you mean the compiler tells you `something` doesn't have a `data` property? – jonrsharpe Sep 17 '17 at 08:51
@jonrsharpe, the property accessor should work, despite of the style. – Nina Scholz Sep 17 '17 at 08:57
Yes, sorry. I'm using typescript and the compiler says to me: 'Property data does not exist on type Object'. – Ivan Lencina Sep 17 '17 at 08:58
1

In fact, the question is: what is the difference between these two ways of declaring and accessing the properties of an object – Ivan Lencina Sep 17 '17 at 08:59
So if you're using TS, *add types*. Turn on the *"no implicit any"* option. – jonrsharpe Sep 17 '17 at 09:00
I'm using Object type in the function declaration, but I did forgot that in the question – Ivan Lencina Sep 17 '17 at 09:02
Anything else you forgot? Please double-check your examples, as presented, and ensure you actually get the outputs you're claiming. `Object` isn't a particularly useful type, you might as well not be using TS if you're not going to give yourself and the compiler a little more help than that. – jonrsharpe Sep 17 '17 at 09:03
It's ionic 2, and it uses typescript. The reason of using Object, is because i saw that in many tutorials, i dont know. Dont hit me. – Ivan Lencina Sep 17 '17 at 09:05
@D.Simon Thank's Simon. It's correct, and that's all I asked. – Ivan Lencina Sep 17 '17 at 09:08

Doubts with Object declaration and accessing properties in TypeScript

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