As the name suggests, union type helps variables to have more than one type. Here is a variable that can have either a
number type or a
string type or a
let a: number | string | boolean;
| is the union operator. All the assignments below are valid due to union operator.
a = 10; a = "Apple"; a = true;
But, if we try to assign an object literal to
a, it throws error as shown below: