Constructor in javascript

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6 Answers

javascriptconstructor
90%

We can use constructor functions to make multiple similar objects,,JavaScript provides constructor functions for many built-in language objects: like Date for dates, Set for sets and others that we plan to study

Example_snippet/controller/utility/_javascript.js/ function User(name) { this.n. . .
function User(name) {
   this.name = name;
   this.isAdmin = false;
}

let user = new User("Jack");

alert(user.name); // Jack
alert(user.isAdmin); // false
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88%

A constructor enables you to provide any custom initialization that must be done before any other methods can be called on an instantiated object, , The ValidationError class doesn't need an explicit constructor, because it doesn't need to do any custom initialization

Example_snippet/controller/utility/_javascript.js/ constructor() { ... } construc. . .
constructor() {
   ...
}
constructor(argument0) {
   ...
}
constructor(argument0, argument1) {
   ...
}
constructor(argument0, argument1, ..., argumentN) {
   ...
}
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72%

In JavaScript, the thing called this is the object that "owns" the code,,The value of this, when used in an object, is the object itself

Example_snippet/controller/utility/_javascript.js/ function Person(). . .
function Person()
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65%

Constructor: A constructor is a function that initializes an object, In JavaScript the constructors are more similar to normal java constructor

Example_snippet/controller/utility/_javascript.js/ var GFG = { subject : "pro. . .
var GFG = {
   subject: "programming",
   language: "JavaScript",
}
Step 2 continued with class GFG { constructor(A,. . .
class GFG {
   constructor(A, B, C) {
      this.g = A;
      this.f = B;
      this.gg = C;
   }
}
Step 3 continued with JavaScript Java. . .
JavaScript
Java
Step 4 continued with var GFG = { articles: 'com. . .
var GFG = {
   articles: 'computer science',
   quantity: 3000,
};
Step 5 continued with GFG.subject: 'JavaScript';. . .
GFG.subject: 'JavaScript';
Step 6 continued with GFG['subject']: 'JavaScript';. . .
GFG['subject']: 'JavaScript';
Step 7 continued with function GFG(a, b, c) { th. . .
function GFG(a, b, c) {
   this.A = a;
   this.B = b;
   this.C = c;
   this.G = "GEEK";
}
Step 8 continued with GFG.n = function () { retu. . .
GFG.n = function() {
   return this.A + this.B;
};
Step 9 continued with function GFG(a, b, c) { th. . .
function GFG(a, b, c) {
   this.A = a;
   this.B = b;
   this.C = c;
   this.n = function() {
      return this.A + this.B;
   }
}
Step 10 continued with function GFG(A, B, C) { th. . .
function GFG(A, B, C) {
   this.g = A;
   this.f = B;
   this.gg = C;
}
Step 11 continued with 1. var object_name = new Objec. . .
1.
var object_name = new Object();
or
var object_name = new Object("java", "JavaScript", "C#");
2.
var object_name = {};
Step 12 continued with object_name . properties = val. . .
object_name.properties = value;
Step 13 continued with object_name [ 'properties'] = . . .
object_name['properties'] = value;
Step 14 continued with Subject: JavaScript Author: Ge. . .
Subject: JavaScript
Author: GeeksforGeeks
Step 15 continued with Subject: JavaScript Author: Ge. . .
Subject: JavaScript
Author: GeeksforGeeks
Step 16 continued with Subject: JavaScript Author: Ge. . .
Subject: JavaScript
Author: GeeksforGeeks
Adding the strings: JavaScript GeeksforGeeks
Step 17 continued with Subject: JavaScript Author: Ge. . .
Subject: JavaScript
Author: GeeksforGeeks
Adding the strings: JavaScript GeeksforGeeks
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75%

A JavaScript constructor method is a special type of method which is used to initialize and create an object, It is called when memory is allocated for an object

Example_snippet/controller/utility/_javascript.js/ 101 Martin Roy . . .
101 Martin Roy
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40%

A constructor is a function that creates an instance of a class which is typically called an “object”, In JavaScript, a constructor gets called when you declare an object using the new keyword

Example_snippet/controller/utility/_javascript.js/ function User(first, last) { . . .
function User(first, last) {
   this.firstName = first
   this.lastName = last
}

var user1 = new User("Jon", "Snow")
console.log(user1)
var user2 = new User("Ned", "Stark")
console.log(user2)
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