to słowo kluczowe w JavaScript Medium
For All Regular function, this points to the WINDOW Object ( Global Context ) .
Enchanting Eel
For All Regular function, this points to the WINDOW Object ( Global Context ) .//this refer to global object or window object
//but when we call this inside method of object it refers to current object
console.log(this===window)//true
let user = {
name: "Shirshak",
age: 25,
sayHi() {
// "this" is the "current object"
console.log(this.name); //print shirshak
}
};
The JavaScript this keyword refers to the object it belongs to.
It has different values depending on where it is used: In a method,
this refers to the owner object. Alone, this refers to the global
object.**Important Points**
1.It creates a new object. The type of this object is object.
2.It sets this new object's internal, inaccessible, [[prototype]] (i.e. __proto__) property to be the constructor function's external, accessible, prototype object (every function object automatically has a prototype property).
3.It makes the this variable point to the newly created object.
4.It executes the constructor function, using the newly created object whenever this is mentioned.
5.It returns the newly created object, unless the constructor function returns a non-null object reference. In this case, that object reference is returned instead.
Note: constructor function refers to the function after the new keyword, as in
new ConstructorFunction(arg1, arg2)// this keyword
// This keyword belongs to the object it belongs to
// (1).Alone, this refers to the global object.
// (2).In a regular function,this refers to the global object.
// (3).In a method, this refers to the owner object.
// 1
console.log(this);
// 2
function abc() {
console.log(this);
}
abc();
// 3
const obj = {
name: "Abhishek",
no: 1,
sum: function (a, b) {
console.log("hello sum", a + b);
console.log("this:::", this);
console.log("this name:::", this.name);
},
};
obj.sum(4, 3);// In JavaScript, the this keyword refers to an object.
const person = {
firstName: "John",
lastName : "Doe",
id : 5566,
fullName : function() {
return this.firstName + " " + this.lastName;
}
};