Array Utilities

Quick Reference

• chunk
• compact
• contains
• countBy
• difference
• drop
• dropLast
• filterMap
• first
• flatten
• groupBy
• intersection
• indexBy
• last
• partition
• replace
• rotate
• sample
• search
• sort
• take
• takeLast
• toggle
• union
• uniq
• unzip
• zip

Common Patterns

import { chunk, compact, filterMap, groupBy, indexBy, partition, sort, toggle, uniq, zip } from '@vielzeug/toolkit';

const raw = [1, 2, 2, 3, 4];
const deduped = uniq(raw); // [1, 2, 3, 4]
const compacted = compact([0, 1, null, 2, undefined, 3]); // [1, 2, 3]

const mapped = filterMap(deduped, (n) => n * 2); // [2, 4, 6, 8]
const filtered = filterMap(deduped, (n) => (n > 2 ? n * 2 : undefined)); // [6, 8]

const pages = chunk(mapped, 2); // [[2,4], [6,8]]

const users = [
  { id: 1, role: 'admin', name: 'Alice' },
  { id: 2, role: 'user', name: 'Bob' },
  { id: 3, role: 'user', name: 'Chris' },
];

const byRole = groupBy(users, (u) => u.role);
const byId = indexBy(users, (u) => u.id);

const sorted = sort(users, { role: 'asc', name: 'asc' });
const tags = toggle(['ts', 'vite'], 'ts'); // ['vite']
const [admins, members] = partition(users, (u) => u.role === 'admin');
const paired = zip(['a', 'b'], [1, 2]); // [['a', 1], ['b', 2]]

console.log(byRole, byId, pages, sorted, tags, compacted, admins, members, paired);

Notes

• filterMap maps values and skips only undefined results.
• compact removes all falsy values, including 0, '', and false.
• For reactive pagination/search sources, use Sourceit: overview and usage.