Cannot redeclare block-scoped variable 'name' In TypeScript

Question

Hi I am learning typescript.

I have in my code.

var name:string="Hello world";
console.log(name);

while compile time I am getting this error.

error TS2451: Cannot redeclare block-scoped variable 'name'.
index.ts(4,5): error TS2451: Cannot redeclare block-scoped variable 'name'.

Can someone describe me why I am getting this error?

Answer 1

The name property is defined on the window object:

interface Window extends EventTarget, WindowTimers, WindowSessionStorage, WindowLocalStorage, WindowConsole, GlobalEventHandlers, IDBEnvironment, WindowBase64, GlobalFetch {
    ...
    name: string;
    ...
}

(https://github.com/Microsoft/TypeScript/blob/master/lib/lib.d.ts#L17226)

You'll need to come up with a new name for your variable:

var myname = "Hello world";
console.log(myname);