TypeScript: Property does not exist on type '{}'

Question

I am using Visual Studio 2013 fully patched. I am trying to use JQuery, JQueryUI and JSRender. I am also trying to use TypeScript. In the ts file I\'m getting an error as follo

Answer 1

When you write the following line of code in TypeScript:

var SUCSS = {};

The type of SUCSS is inferred from the assignment (i.e. it is an empty object type).

You then go on to add a property to this type a few lines later:

SUCSS.fadeDiv = //...

And the compiler warns you that there is no property named fadeDiv on the SUCSS object (this kind of warning often helps you to catch a typo).

You can either... fix it by specifying the type of SUCSS (although this will prevent you from assigning {}, which doesn't satisfy the type you want):

var SUCSS : {fadeDiv: () => void;};

Or by assigning the full value in the first place and let TypeScript infer the types:

var SUCSS = {
    fadeDiv: function () {
        // Simplified version
        alert('Called my func');
    }
};