Javascript Practice Day 4 : Factory,Constructor,Dynmic Prototype and Prototype Pattern

//Reference : https://www.youtube.com/watch?v=xizFJHKHdHw&list=PL7pEw9n3GkoW5bYOhVAtmJlak3ZK7SaDf&index=1
// factory ,constructor prototype pattern

//in factory pattern we create a simple function with parameters which will return an object and thereby
//behaves a factory .

var peopleFactor = function( age, name,state){
    
    var temp={};    ///creating  a empty temp object
    
    temp.age= age;  //attaching the properties to the object
    temp.name=name;
    temp.state=state;
    
    temp.printPerson=function(){
        console.log(this.name+" , "+this.age+ " , "+this.state);
    };
    
    return temp;  //returning the object
};


//creating differernt object from the factory function

var person= peopleFactor('John',23,'CA');  
var person1= peopleFactor('Kim',23,'SC');
var person2= peopleFactor('lun',22,'TX');


//printing the different objects created from the factory
person1.printPerson();
person2.printPerson();




//Constructor Pattern - In constructor patteren we are attaching the properties to the function itself ,as functions are objects
//in javascript.Constructor pattern do not create an object so we have to create objects with new keyword. The problem with constructor pattern //is that all the object will have the properties which any be redundant , So we have the prototype pattern.


//since in Javascript function are object we are associating peoperties to the function itself

var peopleConstructor = function(age,name,state){
  this.name=name;
  this.age=age;
  this.state=state;    

  this.printPerson =function(){
      console.log(this.name+" , "+this.age+" , "+this.state);
  }
    
}

//We are creating different objects on the function

var person4= new peopleConstructor('per4',23,'CA');
var person5= new peopleConstructor('per5',23,'CA');


person4.printPerson();
person5.printPerson();



//Prototype Pattern -- created an empty object and added properties with prototype to it , these will create shared propeties among the objects

//declaring the prototype
var peopleProto = function(){
};

//default properties associated to the prototype properties
peopleProto.prototype.name="";
peopleProto.prototype.age=0;
peopleProto.prototype.state="";

peopleProto.prototype.printPerson = function(){
console.log(this.age+" , "+this.name+" , "+this.state);
}

//create a prototype objects
var per6= new peopleProto();

//associating the properties to object

per6.age=23;
per6.name="Per6";
per6.state="CA";

console.log("From Prototype");
per6.printPerson();


console.log("name" in per6);



//dynamic prototype pattern


var peopleDynamicProto = function(name, age ,state){
    
      this.name=name;
      this.age=age;
      this.state=state;    
    
        //if the funciton is not present then create the function in the prototype space or shared space
        //when the first object is created since no printfunction is available create the fuction in protype space
        // when the second object is created since printfunction is already available no function is created
   
        if(typeof this.printPerson !== 'function'){
            
            peopleDynamicProto.prototype.printPerson = function(){
                    console.log(this.age+" , "+this.name+" , "+this.state);
                }

        }


};

console.log("From Dynamic prototype");
var per7= new peopleDynamicProto("per7",23,"CA");
per6.printPerson();