Extending Object.prototype with TypeScript

Question

I am currently working on a TypeScript API, which requires some additional features binding to the Object prototype (Object.prototype).

Consider the following code:<

Answer 1

I have extended the Array the same way and faced a big problem when s a party was using for i in ... to loop over it. Now you can't control every third party code and these bugs could get really annoying so I suggest a better aprocach:

interface Array {
   crandom(): T;
}

/** Retrieve a random element from the list */
 Object.defineProperty(Array.prototype, 'crandom', { value: function() {

    let index = Math.floor(Math.random() * this.length);

    return this[index];
}
});

Now by using Object.defineProperty your new property won't be enumerated over and it is safe. The above code pretty much gives a random element from the array. I made another one too which pops a random element from array:

Object.defineProperty(Array.prototype, 'popRandom', { value: function() {

    let index = Math.floor(Math.random() * this.length);

    let result = this[index];
    this.splice(index, 1);

    return result;
}
});

with Object.defineProperty You get more control over this creation and you can add additional restrictions too.