How to dynamically assign value to class property in TypeScript
<p>I would like to dynamically assign multiple properties to MyClass in TypeScript so there is no need to write multiple lines of code for setting class properties. I wrote the following code:</p>

<pre><code>interface IMy
{
    visible?: boolean;
    text?: string;
}

class MyClass
{
    element: JQuery;

    assing(o: IMy): void
    {
        for (let [key, value] of Object.entries(o))
        {
            if (typeof value !== "undefined")
                this[key] = value;
        }
    }

    get visible(): boolean
    {
        return this.element.is(":visible");
    }

    set visible(visible: boolean)
    {
        this.element.css("display", visible ? "" : "none");
    }

    get text(): string
    {
        return this.element.html();
    }

    set text(text: string)
    {
        this.element.html(text);
    }
}

let t = new MyClass();
t.assign({ visible: true });
//instead t.visible = true;

//or

t.assign({ text: "Something" });
//instead t.text = "something";

//or

t.assign({ text: "Something", visible: false });
//instead t.visible = true; 
//        t.text = "something";
</code></pre>

<p>but, I have problems in line <code>this[key] = value;</code> with error: </p>

<blockquote>
  <p>Index signature of object type implicitly has an 'any' type.</p>
</blockquote>

<p>What I need to change or my approach is completely wrong?<br>
It would also be a good solution for setting default properties in constructor when interface is constructor parameter.</p>

<p><strong>Edited:</strong><br>
About entries I really liked them so I am using this code:</p>

<pre><code>//extensions.d.ts
interface Object
{
    entries&lt;T&gt;(o: any): [string, T][];
    entries(o: any): [string, any][];
}
//exntesion.js !!note js not ts
if (!Object.entries)
{
    Object.entries = function* entries(obj)
    {
        for (let key of Object.keys(obj))
        {
            yield [key, obj[key]];
        }
    };
}
</code></pre>

<p><strong>Edited 2:</strong></p>

<p>The primary idea was to solve problems for overloading constructor where you could set only desired properties.<br>
Here is the complete code if someone else finds it usable.</p>

<pre><code>interface IMy
{
    prop1?: boolean;
    prop2?: string;
    prop3?: string;
    prop4?: number;
}

class MyClass implements IMy
{
    prop1: boolean = false;
    prop2: string = "";
    prop3: string = "Something";
    prop4: number = 0;

    constructor(properties: IMy)
    {
        this.assing(properties);
    }

    assing(o: IMy): void
    {
        let that = (&lt;any&gt;this);
        for (let key in o)
        {
            if (o.hasOwnProperty(key))
            {
                let value = (&lt;any&gt;o)[key];
                if (typeof value !== "undefined" &amp;&amp; typeof that[key] !== "undefined")
                    that[key] = value;
            }
        }
    }

}

let my1 = new MyClass({ prop1: true });
let my2 = new MyClass({ prop2: "SomeText", prop3: "Anything" });
//I set prop2 and prop3
let my3 = new MyClass({ prop4: 10 });    
//I set prop4 (fourth parameter)

console.log(my1, my2, my3);
</code></pre>