TypeScript Array Utilities

Type-safe utility functions for frequently used array operations in TypeScript development.

emptyArray: Generate Empty Array of Specified Size

Create an array of specific length for initialization, placeholders, or mock data.

function emptyArray(size: number): Array<undefined> {
  return Array(size).fill(undefined);
}

chunkArray: Split Array into Chunks

Split an array into chunks of specified size.

function chunkArray<T>(array: T[], size: number): T[][] {
  if (size <= 0) return [];
  return Array.from({ length: Math.ceil(array.length / size) }, (_, i) =>
    array.slice(i * size, (i + 1) * size),
  );
}

Using Array.from to generate the necessary number of chunks while slicing the original array.

Usage example:

const numbers = [1, 2, 3, 4, 5, 6, 7];

const chunks = chunkArray(numbers, 3);

console.log(chunks);
// Result: [[1, 2, 3], [4, 5, 6], [7]]

filterNonNull: Type-Safe Removal of Null and Undefined

Remove null or undefined from API responses, narrowing TypeScript type from T | null to T.

function filterNonNull<T>(array: Array<(T | null | undefined)>): Array<T> {
  return array.filter((v): v is T => v != null);
}

unsafeShuffle: Randomly Shuffle Array

Shuffle array using Fisher-Yates algorithm. Note this is a destructive operation that modifies the original array.

function unsafeShuffle<T>(array: T[]): T[] {
  for (let i = array.length - 1; i > 0; i--) {
    const j = Math.floor(Math.random() * (i + 1));
    [array[i], array[j]] = [array[j], array[i]];
  }

  return array;
}