type-assertion.ts

interface Obj {
    x: number;
    y: number;
    name: string;
}

//let a = {} as Obj;
let a = <Obj> {} ;
a.x = 232;
console.log(a);

-----------------------------------
  
interface Obj {
    x ?: number;
    y ?: number;
    name ?: string;
}

let a : Obj  =  {} ; // this syntax will give error if you don't have optional parameter.
a.x = 232;
console.log(a);