JAVASCRIPT

what is the use of bind method in javascript

"Variables has local and global scopes. Let's suppose that we have two variables
with the same name. One is globally defined and the other is defined inside a
function closure and we want to get the variable value which is inside the
function closure. In that case we use this bind() method.

code:

var x = 9; // this refers to global "window" object here in the browser

var person = {
  x: 81, // local variable x = 81
  getX: function() {
    return this.x; // "this" = person , so this.x is the same as  person.x
  }
};
//  the next line of code is the most important one (line 17)
var y = person.getX; // It will return 9, because it will call global value of x(var x=9).

var myFunc = y.bind(person); // It will return 81, because it will call local value of x, which is defined in the object called person(x=81).

y(); // return 9 (the global variable);

myFunc();" // return 81 (the loacl variable);

bind in javascript

bind() returns a bound function that, when executed later, will have the correct context ("this") for calling the original function.

bind method in javascript

let obj = {
    name: "Abhi",
    age: 28,
    info: function() {
        console.log(`${this.name}  is  ${this.age} year's old`);//template literals used here
    },
};
let obj1 = {
    name: "Vikash",
    age: 28,
};

obj.info.bind(obj1)(); //since bind methods return a new function so 
//we can directly call that function[()] without pollouting global
//space while assigning a varibale to call that function.
//Always try to make global space neat n clean ,
//dont polloute while assigning unnecessary variables. 

JavaScript Function bind()

		const person = {
name: "John Smith",
getNameAndAddress: function()
{
return this.name;
}

}
const personWithoutGet = {
name: "Jerry Smithers"}

 console.log(person.getName.bind(personWithoutGet);
  }

/*you can think of bind() apply()  and call() ALL as "stealing someone else's function to use."*/
/* victimBeingStolenFrom.functionName.call(theThief) */
/*notice the second variable personWithoutGet does not have a getName function*/
     

What is the use of bind() in JavaScript?

var myButton = {
  content: 'OK',
  click() {
    console.log(this.content + ' clicked');
  }
};

myButton.click();

var looseClick = myButton.click;
looseClick(); // not bound, 'this' is not myButton - it is the globalThis

var boundClick = myButton.click.bind(myButton);
boundClick(); // bound, 'this' is myButton

JavaScript Function bind()

const person = {
  firstName:"John",
  lastName: "Doe",
  fullName: function () {
    return this.firstName + " " + this.lastName;
  }
}

const member = {
  firstName:"Hege",
  lastName: "Nilsen",
}

let fullName = person.fullName.bind(member);

bind() method

var car = {
    registrationNumber: "FT5142",
    brand: "Benz",

    displayDetails: function(){
        console.log(this.registrationNumber+ " " + this.brand );
    }
}
car.displayDetails();


var myCarDetails = car.displayDetails.bind(car);
myCarDetails();

bind in javascript example

var persona = {
  nombre: 'Franco',
  apellido: 'Chequer',

  getNombre: function(){
    var nombreCompleto = this.nombre + ' ' + this.apellido;
    return nombreCompleto;
  }
}

var logNombre = function(){
  console.log(this.getNombre());
}

var logNombrePersona = logNombre.bind(persona);

logNombrePersona(); //'Franco'

Bind() In JavaScript

		  (function()
	  {
		
		const student =
		  {
			  name :'John',
			  getName : function()
			  {
				  return this.name;
			  }
		  }
		  
	let theName =student.getName.bind(student);
	console.log(theName());

	  })()
      /*use bind when you have a function(not one created from a class) that requires a this, and you add the this candidate inside of bind*/

bind method in js

ar bikeDetails = {
    displayDetails: function(registrationNumber,brandName){
    return this.name+ " , "+ "bike details: "+ registrationNumber + " , " + brandName;
  }
}
        
var person1 = {name:  "Vivek"};
        
var detailsOfPerson1 = bikeDetails.displayDetails.bind(person1, "TS0122", "Bullet");
        
// Binds the displayDetails function to the person1 object
        
        
detailsOfPerson1();
// Returns Vivek, bike details: TS0452, Thunderbird

bind method in js

ar bikeDetails = {
    displayDetails: function(registrationNumber,brandName){
    return this.name+ " , "+ "bike details: "+ registrationNumber + " , " + brandName;
  }
}
        
var person1 = {name:  "Vivek"};
        
var detailsOfPerson1 = bikeDetails.displayDetails.bind(person1, "TS0122", "Bullet");
        
// Binds the displayDetails function to the person1 object
        
        
detailsOfPerson1();
// Returns Vivek, bike details: TS0452, Thunderbird

bind (this)

    this.getView().addEventDelegate({
            onBeforeFirstShow: function() {
                // Some codes
            }.bind(this)
        });