JavaScript Advanced Programming Reading notes OOP

about how JavaScript creates objects:1. Factory mode

1  functionCreateperson (name, age, job) {2             varo =NewObject ();3O.name =name;4O.age =Age ;5O.job =job;6O.sayname =function(){7Alert This. Name);8             }; 9             returno;Ten         } One         varPerson1 = Createperson ("Nicholas", "Software Engineer"); A         varPerson2 = Createperson ("Greg", "Doctor");

Cons: No idea of object-oriented2. Constructor Mode

1  functionPerson (name, age, job) {2              This. Name =name;3              This. Age =Age ;4              This. Job =job;5              This. Sayname =function(){6Alert This. Name);7             }; 8         }9         varPerson1 =NewPerson ("Nicholas", "Software Engineer");Ten         varPerson2 =NewPerson ("Greg", "Doctor"); OnePerson1.sayname ();//"Nicholas" APerson2.sayname ();//"Greg"

Cons: 1. Each method in the constructor is recreated once the instance is created, this.sayname = new Function () {alert (this.name);};alert (Person1.sayname = = Person2.sayname); False3. Prototype Mode

1  functionPerson () {2         }3Person.prototype.name = "Nicholas";4Person.prototype.age = 29;5Person.prototype.job = "Software Engineer";6Person.prototype.sayName =function(){7Alert This. Name);8         };9         varPerson1 =NewPerson ();TenPerson1.sayname ();//"Nicholas" One   A         varPerson2 =NewPerson (); -Person2.sayname ();//"Nicholas" -   theAlert (Person1.sayname = = Person2.sayname);//true

Pros: The properties and methods of an object are shareddisadvantage: Object properties need to be re-assignedunderstanding of Prototype objects:prototype and prototype relationships: Prototype (prototype is a property of a constructor) is a pointer to a prototype, and the constructor attribute in the prototype points to the original constructor.  Person.prototype points to the prototype object, Person.prototype.constructor points to person4. Combination of construction mode and prototype mode     

1    functionPerson (name, age, job) {2              This. Name =name;3              This. Age =Age ;4              This. Job =job;5              This. Friends = ["Shelby", "Court"];6         }7Person.prototype = {8 Constructor:person,9Sayname:function () {TenAlert This. Name); One             } A         }; -   -         varPerson1 =NewPerson ("Nicholas", "Software Engineer"); the         varPerson2 =NewPerson ("Greg", "Doctor"); -   -Person1.friends.push ("Van"); -   +alert (person1.friends);//"Shelby,court,van" -alert (person2.friends);//"Shelby,court" +Alert (person1.friends = = = Person2.friends);//false AAlert (Person1.sayname = = = Person2.sayname);//true at  

Pros: Attributes are defined in constructors, constructor and functions are defined in prototypes

JavaScript Advanced Programming Reading notes OOP