JavaScript - get class method reference

In this article, we would like to show you how to get a class method reference in JavaScript. 

The below example presents the use of bind method to create a reference to a function that uses the correct context (from the object).

We use bind method to avoid one of the most common mistakes in JavaScript - trying to assign a method from an object to a new variable to use it later.

Practical example:

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window.text = 'window text'

​

const object = {

    text: 'object text',

    print: function() {

        console.log(this.text);

    }

};

​

object.print();  // 'object text' // works fine

​

var print = object.print;

print(); // 'window text' // incorrect use, common mistake 

​

var objectPrint = object.print.bind(object); // <---- solution

​

objectPrint(); // 'objext text' // works fine after binding

• Function.prototype.bind() - MDN Web Docs