Checks if any value is of the generic type Primitive or specific type from a given type of the generic type Primitives.

const isPrimitive = <
  Type extends Primitive,
  Payload extends object = object
  value: any,
  type?: Primitives,
  callback: ResultCallback<any, Payload> = resultCallback,
  payload?: Payload
): value is Type =>
    ? {
        bigint: isBigInt,
        boolean: isBooleanType,
        number: isNumberType,
        null: isNull,
        string: isStringType,
        symbol: isSymbol,
        undefined: isUndefined,
      }[type](value, callback, payload)
    : callback(
        isNull(value) ||
          (typeof value !== 'object' && typeof value !== 'function'),

Generic type variables


A generic type variable Type constrained by the generic type Primitive type indicates the type of value parameter via the return type value is Type.


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 isPrimitive() function from which it captures its value.


value: any

The value of any type to check.

type?: Primitives

An optional value of the generic type Primitives type indicates against which type the provided value is checked.

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 Type

The return type is a boolean as the result of its statement indicating the value is a generic type variable Type by default equal to Primitive.


The return value is a boolean indicating whether the provided value is a primitive type of the Primitives.

Example usage

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

isPrimitive(1n); // Returns `true` as `value is Primitive`
isPrimitive<bigint>(1n, 'bigint'); // Returns `true` as `value is bigint`
isPrimitive<boolean>(false, 'boolean'); // Returns `true` as `value is boolean`
isPrimitive<number>(27, 'number'); // Returns `true` as `value is number`
isPrimitive<null>(null, 'null'); // Returns `true` as `value is null`
isPrimitive<string>('age', 'string'); // Returns `true` as `value is string`
isPrimitive<symbol>(Symbol(27), 'symbol'); // Returns `true` as `value is symbol`
isPrimitive<undefined>(undefined, 'undefined'); // Returns `true` as `value is undefined`

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