Why does typescript allow any to be used as interface

Question

We are using typescript for one of our larger project and we ran into a bug due to the fact that typescript allows any to be passed when expecting an interface.

Why does typescript allow this or is there a setting that i missed.

The following code sample compiles correctly

interface IInterface{
    InterfaceProperty:string;
}

var prop:any = "2000";

function DoStuff(a:IInterface)
{
    var x = a.InterfaceProperty;
}

// Why am i allowed to pass any as an interface?
DoStuff(prop);

Bruno Grieder · Accepted Answer · 2016-05-26 14:33:06Z

4

From the Typescript handbook:

Any

We may need to describe the type of variables that we do not know when we are writing an application. These values may come from dynamic content, e.g. from the user or a 3rd party library. In these cases, we want to opt-out of type-checking and let the values pass through compile-time checks. To do so, we label these with the any type:

In short with any, you opt-out of type-checking

answered May 26, 2016 at 14:33

Bruno Grieder

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1 Comment

Patrick Over a year ago

Of course... we will need to turn on --noImplicitAny and make sure people don't use any. In my mental image any was like Object in C#, however its more like dynamic in C#. Thanks. Simmilar to question stackoverflow.com/questions/32227277/…

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