Checks if any value is an object type or the type obtained from its object class equal to 'object', and an instance of Object.

const isObject = <Obj = object, Payload extends object = object>(
  value: any,
  callback: ResultCallback<any, Payload> = resultCallback,
  payload?: Payload
): value is Obj =>
    (typeof value === 'object' || typeOf(value) === 'object') &&
      value instanceof Object,

Generic type variables


A generic type variable Obj indicates the type of the given value parameter via the return type value is Obj, by default object.


The Payload generic type variable constrained by object indicates the type of optional parameter payload of the supplied callback function and payload optional parameter of the isObject() function from which it captures its value.


value: any

The value of any type to check.

callback: ResultCallback<any, Payload>

A callback function of ResultCallback type with parameters, the value that has been checked, the result of this check, and payload of generic type variable Payload with optional properties from the provided payload, to handle them before the result return. By default, it uses resultCallback() function.

payload?: Payload

An optional object of the generic type variable Payload is assigned to the payload of the given callback function.

Return type

value is Obj

The return type is a boolean as the result of its statement indicating the value is a generic type variable Obj by default object.


The return value is a boolean indicating whether the provided value is an object.

Example usage

// Example usage.
import { isObject } from '@angular-package/type';

const x = 10304050;
const NUMBER = 10304050;
const STRING = '!@#$%^&*()abcdefghijklmnoprstuwyz';
const SYMBOL_NUMBER: unique symbol = Symbol(NUMBER);
const SYMBOL_STRING: unique symbol = Symbol(STRING);

interface ObjectOne {
  'key as string'?: boolean;
  1030405027?: string;
  5?: string;
  [NUMBER]: number;
  [STRING]: string;
  [SYMBOL_NUMBER]?: string;
  [SYMBOL_STRING]?: number;
  x: number;

const OBJECT_ONE: ObjectOne = {
  'key as string': true,
  1030405027: 'key is number',
  5: 'key is also number',
  [STRING]: 'key is string',
  [SYMBOL_NUMBER]: 'key is symbol number',
  x: 3000

isObject(OBJECT_ONE); // true

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