isNull()

isNull()

Checks if any value is of the type obtained from its object class equal to 'null' or an object type that is equal to null.

is-null.func.ts

const isNull = <Payload extends object>(
  value: any,
  callback: ResultCallback<any, Payload> = resultCallback,
  payload?: Payload
): value is null =>
  callback(
    (typeOf(value) === 'null' || typeof value === 'object') && value === null,
    value,
    payload
  );

Generic type variables

Payloadextendsobject

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 isNull() function from which it captures its value.

Parameters

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 null

The return type is a boolean as the result of its statement.

Returns

The return value is a boolean indicating whether the provided value is null.

Example usage

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

isNull(null); // true
isNull(27); // false