How to Use Static Method in JavaScript: Simple Guide

In JavaScript, a static method is defined inside a class using the static keyword and can be called directly on the class without creating an instance. You use it by calling ClassName.methodName(), not on an object instance.

Syntax

A static method is declared inside a class using the static keyword before the method name. It belongs to the class itself, not to any object created from the class.

• static: keyword to define a static method
• methodName(): the name of the static method
• Called using ClassName.methodName(), not on instances

javascript

class MyClass {
  static myStaticMethod() {
    return 'Hello from static method!';
  }
}

Example

This example shows how to define a static method and call it directly on the class. It also shows that instances of the class cannot call the static method.

javascript

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

// Call static method on the class
console.log(Calculator.add(5, 7));

// Create an instance
const calc = new Calculator();

// Trying to call static method on instance will cause error
// console.log(calc.add(5, 7)); // Uncaught TypeError

Output

12

Common Pitfalls

One common mistake is trying to call a static method on an instance of the class instead of the class itself. Static methods are not available on instances.

Another mistake is forgetting to use the static keyword, which makes the method an instance method instead.

javascript

class Person {
  // Wrong: missing static keyword
  greet() {
    return 'Hello!';
  }
}

const p = new Person();
console.log(p.greet()); // Works because greet is instance method

// Correct way with static
class PersonStatic {
  static greet() {
    return 'Hello!';
  }
}

console.log(PersonStatic.greet()); // Works
// console.log(new PersonStatic().greet()); // Error: greet is not a function

Output

Hello!
Hello!

Quick Reference

Remember these key points about static methods:

• Use static keyword inside class to define them.
• Call them on the class itself, not on instances.
• Useful for utility functions related to the class but not to individual objects.

Key Takeaways

Static methods belong to the class, not to instances.

Use the static keyword to define a static method inside a class.

Call static methods using ClassName.methodName(), not instance.methodName().

Trying to call static methods on instances causes errors.

Static methods are great for utility functions related to the class.