CODEWITHSUNDEEP
typescript
saurabh vats
saurabh vats

Reputation: 369

Typescript: If am defining a variable type as interface type am getting error

In the below code I am getting an error in statement (emp:IEmployee= { FirstName: "Saurabh", LastName: "Vats" };) when am trying to define a variable as interface type. Why is TypeScript is giving me error here?

class Greeter {
    element: HTMLElement;
    span: HTMLElement;
    timerToken: number;
    constructor(element: HTMLElement) {
        this.element = element;
        this.element.innerHTML += "The time is: ";
        this.span = document.createElement('span');
        this.element.appendChild(this.span);
        this.span.innerText = new Date().toUTCString();
    }

    start() {
        this.timerToken = setInterval(() => this.span.innerHTML = new Date().toUTCString(), 500);
    }

    stop() {
        clearTimeout(this.timerToken);
    }

    print(employee: IEmployee) {
        console.log(employee.FirstName + employee.LastName);

    }

}

interface IEmployee {
    FirstName: string;
    LastName: string;
}
window.onload = () => {
    var el = document.getElementById('content');
    var greeter = new Greeter(el);
    greeter.start();
    emp:IEmployee= { FirstName: "Saurabh", LastName: "Vats" };
    greeter.print(emp);

};

Upvotes: 1

Views: 50

Answers (1)

Andrew Shepherd
Andrew Shepherd

Reputation: 45222

You're just missing a keyword.

This is incorrect:

emp:IEmployee= { FirstName: "Saurabh", LastName: "Vats" };

It should be:

let emp:IEmployee= { FirstName: "Saurabh", LastName: "Vats" };

But what if, for some reason, you wanted to make it a global variable?

In javascript, if you had written:

emp = { FirstName: "Saurabh", LastName: "Vats" };

You would actually be adding this to the window object.

You can still do this in typescript, you just have to be explicit about it:

interface Window {
    emp:IEmployee;
}

window.onload = () => {
     var el = document.getElementById('content');
     var greeter = new Greeter(el);
     greeter.start();
     window.emp = { FirstName: "Saurabh", LastName: "Vats" };
     greeter.print(emp);
};

Upvotes: 2

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