When arrays are recalled, access to functions is lost for Javascript object instances

Question

When arrays are recalled, access to functions is lost for Javascript object instances

Check out this code snippet I have:

var cobj = {
  a: 0,
  b: 0,
  c: 0,
  asdinit: function(x, y, w, h) {
    this.a = x;
    this.b = y;
    this.c = w;
    this.h = h;
  },
  adsfads: function(a, b, c, d) {
    this.a = a;
    this.b = b;
    this.c = c;
  }
}

var c = new cobj.asdinit(1, 1, 1, 1);
var bigarray = []
for (t = 0; t < 10; t++) {
  var newobj = new cobj.asdinit(1, 1, 1, 1);
  bigarray.push(newobj);
}
for (t = 0; t < 10; t++) {
  var localobj = bigarray[t];
  localobj.adsfads(1, 1, 1, 1);
}

Upon object creation, all functions are accessible. However, after being retrieved from the array, the functions seem to be no longer available. Why is that?

javascript arrays object prototype

Answer 1

Answer №1

To improve your code, consider restructuring it so that a function is responsible for returning objects.

var objectCreator = function() {
  return {
    a: 0,
    b: 0,
    c: 0,
    initialize: function(x, y, w, h) {
      this.a = x;
      this.b = y;
      this.c = w;
      this.h = h;
    },
    updateValues: function(a, b, c, d) {
      this.a = a;
      this.b = b;
      this.c = c;
    }
  }
}.bind(this)

var objectInstance = objectCreator();
var c = objectInstance.initialize(1, 1, 1, 1);
var array = []
for (t = 0; t < 10; t++) {
  var newObj = new objectInstance.initialize(1, 1, 1, 1);
  array.push(newObj);
}
for (t = 0; t < 10; t++) {
  var localObject = array[t];
  localObject.updateValues(1, 1, 1, 1);
}

Answer 2

To improve your code, consider restructuring it so that a function is responsible for returning objects.

var objectCreator = function() {
  return {
    a: 0,
    b: 0,
    c: 0,
    initialize: function(x, y, w, h) {
      this.a = x;
      this.b = y;
      this.c = w;
      this.h = h;
    },
    updateValues: function(a, b, c, d) {
      this.a = a;
      this.b = b;
      this.c = c;
    }
  }
}.bind(this)

var objectInstance = objectCreator();
var c = objectInstance.initialize(1, 1, 1, 1);
var array = []
for (t = 0; t < 10; t++) {
  var newObj = new objectInstance.initialize(1, 1, 1, 1);
  array.push(newObj);
}
for (t = 0; t < 10; t++) {
  var localObject = array[t];
  localObject.updateValues(1, 1, 1, 1);
}

Answer 3

Answer №2

Utilizing the asdinit and adsfads functions as constructors results in objects with only a, b, and c properties, lacking prototype methods.

An alternative approach could be:

class cobj {
  constructor (x, y, w, h) {
    this.a = x
    this.b = y
    this.c = w
    this.h = h
  }
  
  adsfads (a, b, c, d) {
    this.a = a
    this.b = b
    this.c = c
  }
}

var bigarray = []
for (t = 0; t < 2; t++) {
  var newobj = new cobj(t, t, t, t);
  bigarray.push(newobj);
}
for (t = 0; t < 2; t++) {
  var localobj = bigarray[t];
  localobj.adsfads(t + 1, t + 1, t + 1, t + 1);
  console.log(localobj)
}

For more information, refer to https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Classes

In ES5, the equivalent would be:

function cobj(x, y, w, h) {
  this.a = x
  this.b = y
  this.c = w
  this.h = h
}

cobj.prototype.adsfads = function(a, b, c, d) {
  this.a = a
  this.b = b
  this.c = c
}

Answer 4

Utilizing the asdinit and adsfads functions as constructors results in objects with only a, b, and c properties, lacking prototype methods.

An alternative approach could be:

class cobj {
  constructor (x, y, w, h) {
    this.a = x
    this.b = y
    this.c = w
    this.h = h
  }
  
  adsfads (a, b, c, d) {
    this.a = a
    this.b = b
    this.c = c
  }
}

var bigarray = []
for (t = 0; t < 2; t++) {
  var newobj = new cobj(t, t, t, t);
  bigarray.push(newobj);
}
for (t = 0; t < 2; t++) {
  var localobj = bigarray[t];
  localobj.adsfads(t + 1, t + 1, t + 1, t + 1);
  console.log(localobj)
}

For more information, refer to https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Classes

In ES5, the equivalent would be:

function cobj(x, y, w, h) {
  this.a = x
  this.b = y
  this.c = w
  this.h = h
}

cobj.prototype.adsfads = function(a, b, c, d) {
  this.a = a
  this.b = b
  this.c = c
}

When arrays are recalled, access to functions is lost for Javascript object instances

Answer №1

Answer №2

Similar questions

How to retrieve the latest document from every sender within a JavaScript array using Mongoose/MongoDB queries

ExtJS web displays appear differently when viewed on Chrome's toggle device mode versus a mobile browser

Unable to retrieve data from SpringBoot controller using $http.get request

Error: Unable to locate module 'child_process' in the context of NextJS + Nightmare

What is the best way to add new input fields dynamically using the push() function in AngularJS?

Calculating the mean of elements in 3D arrays using Numpy element-wise operations

Is there a way to access the value of an IPC message beyond just using console log?

Switch from using fetch to utilizing axios for making API requests

Enhancing functionality with jQuery: updating multiple input fields at

Is the object returned by the useParams hook maintained across renders?

What is the best way to transfer information from JavaScript to a JSON database using the fetch API?

Encountering Syntax Error while running `ionic serve` in IONIC2

Receiving a "Maximum call exceeded" error when using Vue.js router guards for the beforeEach hook

AngularJS directive that offers dynamic functionality

Executing an external JavaScript function from within an internal JavaScript code block

What is the best way to delay JavaScript execution until after React has finished rendering?

Struggling with setting up a PHP and Ajax registration and login system

Is there a way to verify the authenticity of a survey depending on the types of form elements used

Validating date parameter in Wiremock request - How to ensure dynamic date matching during testing?

Ways to implement the tabIndex attribute in JSX