singleton-pattern

Implement the Singleton pattern to manage a single shared instance.

Updated Oct 26, 2025

Search Tags:#javascript #oop #singleton #design-pattern #global-state #single-instance

Ready to run

npx skills add https://github.com/jcsoftdev/pulzifi-back --skill singleton-pattern-jcsoftdev

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Please help me install this Agent Skill.
Skill: singleton-pattern
Source: https://github.com/jcsoftdev/pulzifi-back/tree/main/.claude/skills/singleton-pattern
Command: npx skills add https://github.com/jcsoftdev/pulzifi-back --skill singleton-pattern-jcsoftdev

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

Coordinating actions across an application often requires a single, globally accessible instance to manage shared state or resources. This Skill demonstrates how to implement and use a Singleton to ensure only one instance exists and is reused everywhere.

Core Features & Use Cases

Enforces a single instance of a class or object.
Provides a global access point for shared state, configuration, or resources.
Ideal for coordinating logging, caching, or configuration in multi-module applications.

Quick Start

Instantiate the singleton once and import the instance where needed.

Frequently Asked Questions about singleton-pattern

High-intent search queries and answers about installing and using this skill.

FAQPage Schema

What is the singleton pattern in JavaScript and when should I use it?▼

The singleton pattern in JavaScript ensures only one instance of a class exists. Use it to manage global state, centralized configuration, or shared resources like logging and caching across multiple modules.

How do I implement a singleton class to manage global state in JavaScript?▼

To implement a singleton for global state, create a JavaScript class that checks for an existing instance upon instantiation and returns it. You can then export a frozen instance to prevent any further modification.

Can I use a singleton for centralized configuration across multiple modules?▼

Yes, you can use a singleton for centralized configuration across modules. It provides a single global access point, ensuring that all parts of your application reuse the same configuration instance without creating duplicates.

How does a frozen singleton instance prevent unwanted state modification?▼

A frozen singleton instance prevents unwanted state modification by locking the exported object. This ensures the shared global state or configuration remains read-only and cannot be accidentally altered by other modules importing the instance.

What are the limitations of using a singleton pattern for shared resources?▼

A limitation of the singleton pattern for shared resources is the potential introduction of tight coupling across modules. Overusing singletons for global state can make dependencies hidden and complicate unit testing due to shared, persistent state.