Get type of object in TypeScript

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Category: Type | Language: TypeScript

In TypeScript, you can determine the type of an object using the typeof and instanceof operators.

The typeof operator returns a string representation of the type of an object or variable.

Here is an example:

let name: string = "John";
let age: number = 28;
let isStudent: boolean = true;

console.log(typeof name); // string
console.log(typeof age); // number
console.log(typeof isStudent); // boolean

The instanceof operator is used to check whether an object is an instance of a particular class or interface.

Here is an example:

class Person {
  name: string;
  age: number;

constructor(name: string, age: number) {
this.name = name;
this.age = age;
}
}

let john = new Person("John", 28);
console.log(john instanceof Person); // true

let obj = { x: 1, y: 2 };
console.log(obj instanceof Person); // false

In the above example, john is an instance of the Person class, so the instanceof operator returns true. obj is not an instance of the Person class, so false is returned.