moyal.js.linq

A lightweight, zero-dependency JavaScript library that brings LINQ-style querying capabilities to native arrays. Designed for both clarity and performance, it offers a fluent, chainable API for filtering, projecting, grouping, ordering, and aggregating data—without relying on external frameworks.

Information

• Current Version: 1.0.4
• Author: Ilan Moyal
• Website: https://www.moyal.es
• License: MIT
• NPM: https://www.npmjs.com/package/@moyal/js-linq
• API Documentation: View online

Table of Contents

• Installation
• Importing
• Features
• Quick Start
• API Overview
• Version Access
• Example files and test files
• License
• Author

Installation

npm install @moyal/js-linq

Importing

In Node.js (ES Module)

import { Linq } from "@moyal/js-linq";

In Node.js (CommonJS)

const { Linq } = require("@moyal/js-linq");

In the Browser (ES Module via CDN)

<!-- From jsDelivr CDN (minified version) -->
<script type="module">
  import "https://cdn.jsdelivr.net/npm/@moyal/[email protected]/dist/moyal.linq.umd.min.js";
</script>

<!-- From jsDelivr CDN (non minified version with documentation) -->
<script type="module">
  import "https://cdn.jsdelivr.net/npm/@moyal/[email protected]/dist/moyal.linq.umd.js";
</script>

Or using unpkg:

<script type="module">
  import "https://unpkg.com/@moyal/[email protected]/dist/moyal.linq.umd.min.js";
</script>

Features

• Fully Chainable: Every operation returns a LINQ-like wrapper to continue your query seamlessly.
• Deferred Execution: Most operations are lazily evaluated using generators.
• Zero Dependencies: No third-party libraries required. Works in both Node.js and browsers.
• Rich Set of Operators: Includes filtering, projection, ordering, joining, grouping, set operations, aggregation, and statistics.
• Built-in Statistics: Easily compute count, sum, average, median, mode, variance, and standard deviation.
• Extensible Comparers & Selectors: All key-based operations support custom comparison and projection logic.
• Supports thisArg Binding: Pass custom context for user-defined callbacks.
• Typed Statistics API: Strongly encapsulated results with .clone(), .equal(), and .toJSON() support.

Quick Start

import { Linq } from '@moyal/js-linq';

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

const result = Linq
    .from(numbers)
    .where(x => x % 2 === 0)
    .select(x => x * 10)
    .toArray();

console.log(result); // Output: [20, 40, 60]

/*

In this quick start example:

- We filter out odd numbers.
- We multiply each number in 10.
- Dumping the result iterable to array.

*/

For more code examples, see also "/examples" and (or) "/test/units" in GitHub Repository.

API Overview

| Method / Static | Purpose | |----------------|---------| | from(iter) | Start LINQ chain from iterable | | aggregate(seed, fn) | Accumulate values with custom logic | | all(fn) | Check if all elements match predicate | | any([fn]) | Check if any element exists or matches | | append(value) | Append a value to the sequence | | average() | Compute average (returns undefined if non-numeric) | | concat(...iterables) | Concatenate multiple sequences | | contains(value, [comparer]) | Check for value presence | | count() | Count elements | | defaultIfEmpty(val) | Provide default if empty | | distinct([comparer]) | Unique values with optional comparer | | duplicate(n, inplace) | Repeat sequence n times | | elementAt(i) / elementAtOrDefault(i, def) | Get item by index (or fallback) | | empty() | Return an empty sequence | | except(other, [comparer]) | Exclude items in another iterable | | first([fn]) / firstOrDefault(def, [fn]) | Get first (matching) element | | forEach(fn) | Run function for each item | | groupBy(keyFn, elFn, resFn, cmp) | Group by key with full control | | groupJoin(...) | Join left with grouped-right by key | | intersect(other, [cmp]) | Common unique elements | | join(...) | Standard inner join | | last([fn]) / lastOrDefault(def, [fn]) | Get last (matching) element | | max([cmp]) / min([cmp]) | Get maximum/minimum value | | orderBy([keyFn], [cmp]) | Sort ascending | | orderByDescending(...) | Sort descending | | thenBy(...) / thenByDescending(...) | Chain ordering | | prepend(value) | Add value at start | | range(start, count) | Generate integer range | | removeNullishes() | Filter out null/undefined | | repeat(value, count) | Repeat value count times | | reverse() | Reverse sequence | | select(fn) | Transform each element | | selectMany(collFn, resFn) | Flatten nested sequences | | sequenceEqual(other, [cmp]) | Compare two sequences | | single([fn]) / singleOrDefault(def, [fn]) | Enforce single (matching) element | | skip(n) / skipLast(n) | Skip n items (from start/end) | | skipWhile(fn) | Skip until predicate fails | | statistics([extended]) | Return statistics object | | sum() | Sum of all elements | | take(n) / takeLast(n) | Take n items (from start/end) | | takeWhile(fn) | Take while predicate passes | | toArray() | Convert to array | | toMap(keyFn, valFn) | Build Map from sequence | | toDictionary(...) | Alias for toMap | | toSet([keyFn]) | Build Set from sequence | | where(fn) | Filter by predicate | | union(other, [cmp]) | Union of sequences (unique values) | | zip(iter1, iter2, transform) | Zip two sequences with transform | | Statistics | Encapsulates count, average, median, mode, etc. |

Note: Many methods support optional thisArg to bind context in user-defined functions.

Version Access

Access the library version directly:

import * as myLib from "@moyal/js-linq";

myLib.Version // → e.g., "1.0.4"

License

MIT License - free to use, modify, and distribute.

Author: Ilan Moyal

Website: https://www.moyal.es

GitHub: Ilan Moyal

LinkedIn: Ilan Moyal