How to write a object oriented Node.js model

node js model structure
node js model example
node js create model class
node js class es6
node js class objects
how to create object in node js
node js model mysql
node.js class tutorial

I am having a lot of trouble writing an object oriented Cat class in Node.js. How can I write a Cat.js class and use it in the following way:

// following 10 lines of code is in another file "app.js" that is outside 
// the folder "model"
var Cat = require('./model/Cat.js');

var cat1 = new Cat(12, 'Tom');
cat1.setAge(100);
console.log(cat1.getAge()); // prints out 100 to console

var cat2 = new Cat(100, 'Jerry');
console.log(cat1.equals(cat2)); // prints out false

var sameAsCat1 = new Cat(100, 'Tom');
console.log(cat1.equals(sameAsCat1)); // prints out True

How would you fix the following Cat.js class I have written:

 var Cat = function() {
    this.fields = {
        age: null,
        name: null
    };

    this.fill = function (newFields) {
        for(var field in this.fields) {
            if(this.fields[field] !== 'undefined') {
                this.fields[field] = newFields[field];
            }
        }
    };

    this.getAge = function() {
        return this.fields['age'];
    };

    this.getName = function() {
        return this.fields['name'];
    };

    this.setAge = function(newAge) {
        this.fields['age'] = newAge;
    };

    this.equals = function(otherCat) {
        if (this.fields['age'] === otherCat.getAge() && 
            this.fields['name'] === otherCat.getName())  {
            return true;
        } else {
            return false;
        }
    };
};

module.exports = function(newFields) {
    var instance = new Cat();
    instance.fill(newFields);
    return instance;
};

If I were to design an object like this, then I would have done like this

function Cat(age, name) {       // Accept name and age in the constructor
    this.name = name || null;
    this.age  = age  || null;
}

Cat.prototype.getAge = function() {
    return this.age;
}

Cat.prototype.setAge = function(age) {
    this.age = age;
}

Cat.prototype.getName = function() {
    return this.name;
}

Cat.prototype.setName = function(name) {
    this.name = name;
}

Cat.prototype.equals = function(otherCat) {
    return otherCat.getName() == this.getName()
        && otherCat.getAge() == this.getAge();
}

Cat.prototype.fill = function(newFields) {
    for (var field in newFields) {
        if (this.hasOwnProperty(field) && newFields.hasOwnProperty(field)) {
            if (this[field] !== 'undefined') {
                this[field] = newFields[field];
            }
        }
    }
};

module.exports = Cat;     // Export the Cat function as it is

And then it can be used like this

var Cat = require("./Cat.js");

var cat1 = new Cat(12, 'Tom');
cat1.setAge(100);
console.log(cat1.getAge());                 // 100

var cat2 = new Cat(100, 'Jerry');
console.log(cat1.equals(cat2));             // false

var sameAsCat1 = new Cat(100, 'Tom');
console.log(cat1.equals(sameAsCat1));       // true

var sameAsCat2 = new Cat();
console.log(cat2.equals(sameAsCat2));       // false

sameAsCat2.fill({name: "Jerry", age: 100});
console.log(cat2.equals(sameAsCat2));       // true

Object-oriented JavaScript for beginners, cover OOP in Javascript by example; point out a few caveats and recommended <anonymous> (/home/m/mnt/book/code/06_oop/constructors.js:7:3) at Module. In such cases you create a Node.js module with all the required functions in it. In this Node.js Tutorial, we shall learn how to create a Node.js module, and include it in Node.js file with an Example. Create a Node.js Module. A Node.js Module is a .js file with one or more functions. Following is the syntax to define a function in Node.js module :

6. Objects and classes by example, etc., but with the new Javascript standard ES6, we got a real nice and clear syntax for creating classes. Let's take a simple “Person” example. This� Using Cfx to develop a JavaScript control class library.

I would use TypeScript:

class Cat{
    fields = {
        age: null,
        name: null
    };

    fill(newFields) {
        for(var field in this.fields) {
            if(this.fields[field] !== 'undefined') {
                this.fields[field] = newFields[field];
            }
        }
    }

    getAge() {
        return this.fields.age;
    }

    setAge(newAge:number) {
        this.fields.age = newAge;
    }
}

export = Cat;

You can see the javascript it generates.

TypeScript can be used in both NodeJS and Browser.

How to use classes in Node.js (with no pre-compilers), and why you , In modern versions of node.js (v6.0 or v4.x in strict mode) or when using an ES6 transpiler, you can use the ES6 class keyword: class Student� The latter, known as object literal syntax, is preferred. We can specify the contents of objects using object literal syntax. We can specify member names and values at initialization time:

This code is working fine Person.js code here

  exports.person=function(age,name)
    {
        age=age;
        name=name;
        this.setAge=function(agedata)
        {
           age=agedata;
        }
        this.getAge=function()
        {
            return age;
        }
        this.setName=function(name)
        {
            name=name;
        }
        this.getName=function()
        {
            return name;
        }

};

call object code:

var test=require('./route/person.js');
var person=test.person;
var data=new person(12,'murugan');
data.setAge(13);
console.log(data.getAge());
data.setName('murugan');
console.log(data.getName());

Defining an OOP structure for a Student class in NodeJS, Open another terminal and type: npm install 4. convert server_old into classes. In this video Duration: 6:56 Posted: Dec 22, 2016 Node.js and Object Oriented Programming Sunday, 22nd July 2012, 23:46. Javascript is so nearly a good OOP language, it just lacks classes and inheritance. Luckily you can simulate most of that with a simple function that copies prototypes between objects.

How to Use Classes in Node.js, In MVC your models are objects that save out to the data store and The trouble with writing models is sometimes you want an instance of an object which user. js **/ User.prototype.save = function (callback) { var self = this;� Javascript is an object-oriented programming language that supports delegating inheritance based on prototypes. Each object has a prototype property, which refers to another (regular) object. Properties of an object are looked up from two places: the object itself (Obj.foo), and

How to structure your NodeJS Models, All patterns lend themselves quite easily to the OOP paradigm. By pasting the above code into a Node.js REPL or even your browser's Some examples are the HTTP module, any database driver, and even socket.io,� In general, Mongoose makes it even easier to use MongoDB with Node.js. Initializing and connecting. Connecting to a MongoDB instance with Mongoose is straight-forward, requiring only the resource URL of the database. The sample app establishes a connection and object model with Mongoose in its app.js file.

Design patterns in Node.js: A practical guide, JavaScript is not a class-based object-oriented language. But it still has ways of The most popular model of OOP is class-based. But as I The following example is a general usage of a class in JavaScript: class Animals� Node.js Tutorial - Node.js Class Creation « Previous; Next » Functions that return objects are a great way to create similar objects. Example. The following code shows how to create an object using this pattern.

Comments
  • Whether this is the only issue, I cannot say, but you want to test typeof() !== 'undefined' in your fill function. And because you assign them null values, that wouldn't work out anyway, because you'll get 'object' back on typeof. If you just assign them as undefined and test for that via typeof(), it would otherwise appear it should behave as you expect.
  • What exactly is the problem you need help with?
  • You might want to have a look at TidBits OoJs. It's reliable and gives you about all OO features you might dream of except for multiple inheritance in a simple and natural syntax.
  • @Chingy I am assuming yours. Try with == instead of === :)
  • or now better in ES6.
  • I came to give the same answer and saw this -4 answer, omg. What's wrong with it?