Javascript bind Function Implementation

Question

I want to Create Polyfill for bind function of javascript for the browser which does not support bind function. Anyone, please tell how bind function is implemented in javascript.

Answer 1

In its simplest form, bind is just a wrapper for apply:

function bind(fn, thisObj) {
  return function() {
    return fn.apply(thisObj, arguments);
  }
}

Answer 2

Implemented the basic functionality of bind by using apply. I called this method myBind, added it to the function prototype so that it's accessible by any function:

Function Implementation

Function.prototype.myBind = function() {
const callerFunction = this;
const [thisContext, ...args] = arguments;
return function() {
    return callerFunction.apply(thisContext, args);
}

}

Usage: Can be used as a native bind function taking in the context and arguments.

function testMyBind(favColor) {
   console.log(this.name, favColor); // Test, pink
}

const user = {
   name: 'Test'
}

const bindedFunction = testMyBind.myBind(user, 'pink');
bindedFunction();