Guards the value to be an array of a generic type variable Type.

const guardArray = <Type, Payload extends object = object>(
  value: Array<Type>,
  callback?: ResultCallback<Array<Type>, Payload>,
  payload?: Payload
): value is Array<Type> => isArray(value, callback, payload);

Generic type variables


A generic type variable Type indicates captured array element type of the given value via the return type and the value parameter of the provided callback function ResultCallback 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 guardArray() function from which it captures its value.


value: Array<Type>

An array of generic type variable Type to guard.

callback?: ResultCallback<Array<Type>, Payload>

The optional 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 Array<Type>

The return type is a boolean as the result of its statement indicating the value is an Array of a generic type variable Type, by default equal to the array element type of the supplied value.


The return value is a boolean indicating whether the value is an Array of a generic type variable Type.

Example usage

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

guardArray([1, 2, 3]); // true. value is number[]
guardArray([1, '2', 3]);  // true. value is (string | number)[]
guardArray([1, '2', 3n]); // true value is (string | number | bigint)[]
guardArray([1, '2', 3n, undefined]);
guardArray([1, '2', 3n, undefined, null]);
guardArray([1, '2', 3n, undefined, null, Symbol(6), ]);
guardArray([1, '2', 3n, undefined, null, Symbol(6), true]);

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