JavaScript

Static methods are functions defined on a class itself, not on instances of the class. They are often used for utility functions, factory methods, or any behavior that doesn’t rely on an individual instance.

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📌 What is a Static Method?

In JavaScript, you define a static method using the static keyword inside a class.

class MathHelper {
  static add(a, b) {
    return a + b;
  }
}

🧠 How to Use It

You call a static method on the class itself, not on an object created from the class:

console.log(MathHelper.add(5, 3)); // Output: 8

Trying to call it on an instance will throw an error:

const math = new MathHelper();
console.log(math.add(5, 3)); // ❌ TypeError: math.add is not a function

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🧩 Real-Life Example

class User {
  constructor(name) {
    this.name = name;
  }

  greet() {
    console.log(`Hello, ${this.name}`);
  }

  static createGuestUser() {
    return new User("Guest");
  }
}

const guest = User.createGuestUser();
guest.greet(); // Output: Hello, Guest

Here, createGuestUser() is a static method that acts like a factory to return a default user.

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🧠 Key Points

Feature	Description
Defined with static	Use the static keyword inside the class
Called on the class	Not accessible from instances
Common use cases	Utilities, helper functions, factory patterns

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❗ When to Use Static Methods

• When the method logic does not need access to instance properties (this).
• For utility functions or calculations related to the class but not tied to a specific object.
• To implement the Factory Pattern or reusable helper methods.

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🔁 Static vs Instance Method

Feature	Static Method	Instance Method
Called on	Class itself (ClassName.method())	Object instance (object.method())
Access to this	Refers to the class itself	Refers to the instance
Purpose	Utility or helper logic	Behavior specific to an instance

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✅ Summary

Static methods in JavaScript are powerful tools for keeping reusable logic out of object instances. They help write cleaner and more organized code, especially when implementing utility functions or static factory methods.

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