some

The some utility checks if at least one element in an array satisfies a given condition. It stops iterating as soon as it finds a match, making it efficient for large datasets. Unlike the native Array.prototype.some, this version supports asynchronous predicates.

Implementation

View Source Code

import { assert } from '../function/assert';
import { IS_ARRAY_ERROR_MSG, isArray } from '../typed/isArray';
import type { Predicate } from '../types';

/**
 * Checks if at least one element in the array satisfies the provided predicate function.
 *
 * @example
 * ```ts
 * some([1, 2, 3], (n) => n === 2) // true
 * some([1, 2, 3], (n) => n === 4) // false
 * ```
 *
 * @param array - The array to be checked.
 * @param predicate - The function to test each element of the array.
 *
 * @returns `true` if at least one element satisfies the predicate, otherwise `false`.
 *
 * @throws {TypeError} If the provided array is not an array.
 */
export function some<T>(array: T[], predicate: Predicate<T>) {
  assert(isArray(array), IS_ARRAY_ERROR_MSG, { args: { array }, type: TypeError });

  for (let index = 0; index < array.length; index++) {
    if (predicate(array[index], index, array)) {
      return true;
    }
  }

  return false;
}

some.fp = true;

Features

• Isomorphic: Works in both Browser and Node.js.
• Short-circuiting: Stops execution as soon as a match is found for better performance.
• Type-safe: Properly typed predicate support.

API

function some<T>(array: T[], predicate: (item: T, index: number, array: T[]) => boolean): boolean;

Parameters

• array: The array to check.
• predicate: The function to test each element. It receives:
  • item: The current element.
  • index: The index of the current element.
  • array: The original array.

Returns

• true if the predicate returns truthy for any element; otherwise, false.

Examples

Basic Validation

import { some } from '@vielzeug/toolkit';

const numbers = [1, 3, 5, 7, 8];

// Check for even numbers
const hasEven = some(numbers, (x) => x % 2 === 0); // true

Checking Object Properties

import { some } from '@vielzeug/toolkit';

const users = [
  { id: 1, role: 'user' },
  { id: 2, role: 'editor' },
  { id: 3, role: 'user' },
];

// Check if any admin exists
const hasAdmin = some(users, (u) => u.role === 'admin'); // false

Implementation Notes

• Throws TypeError if the first argument is not an array.
• Returns false for an empty array, regardless of the predicate.
• Does not modify the original array.

See Also

• every: Check if all elements satisfy a condition.
• filter: Get all elements that satisfy a condition.
• find: Get the first element that satisfies a condition.