Contenido del Curso
Object-Oriented Programming in JavaScript
Object-Oriented Programming in JavaScript
Constructor
Constructor is used for object creation and specifying some attributes. Look at this statement:
student = new Student();
Student()
is a constructor of class Student
, so the student
variable is now a Student
object.
This simple constructor is using by default and creates an object only. But you can define a constructor that will initialize some object attributes.
student = new Student('Robert', 22);
student
object now has name Robert and age 22.
The syntax of the constructor inside the class is following:
class Student{ name; university; age; gpa; constructor(name, age){ this.name = name; this.age = age; console.log('Student created'); } sleep(){ console.log('I am sleeping right now!'); } happyBirthday(){ this.age += 1; console.log('Today is my birthday'); } } student = new Student('Robert', 22);
By object creating, you can pass some arguments and use them inside constructor. But note that skipped parameters will have undefined
value. Look at the example and run it to see what happens.
class Student{ name; age; gpa; constructor(name, age, gpa){ // constructor with 3 parameters this.name = name; this.age = age; this.gpa = gpa; console.log('Student created'); } } student = new Student('Robert', 22); // pass only 2 values console.log(JSON.stringify(student)); // object has only 2 defined properties name and age
Only name
and age
properties are defined in student
object because of 2 arguments while student
initialization.
Pass the arguments in order they are defined in constructor.
Tarea
Extend existing constructor with arguments for university
and gpa
attributes. After that, change the line of object initialization by adding 2 more arguements inside Student()
statement.
¡Gracias por tus comentarios!
Constructor
Constructor is used for object creation and specifying some attributes. Look at this statement:
student = new Student();
Student()
is a constructor of class Student
, so the student
variable is now a Student
object.
This simple constructor is using by default and creates an object only. But you can define a constructor that will initialize some object attributes.
student = new Student('Robert', 22);
student
object now has name Robert and age 22.
The syntax of the constructor inside the class is following:
class Student{ name; university; age; gpa; constructor(name, age){ this.name = name; this.age = age; console.log('Student created'); } sleep(){ console.log('I am sleeping right now!'); } happyBirthday(){ this.age += 1; console.log('Today is my birthday'); } } student = new Student('Robert', 22);
By object creating, you can pass some arguments and use them inside constructor. But note that skipped parameters will have undefined
value. Look at the example and run it to see what happens.
class Student{ name; age; gpa; constructor(name, age, gpa){ // constructor with 3 parameters this.name = name; this.age = age; this.gpa = gpa; console.log('Student created'); } } student = new Student('Robert', 22); // pass only 2 values console.log(JSON.stringify(student)); // object has only 2 defined properties name and age
Only name
and age
properties are defined in student
object because of 2 arguments while student
initialization.
Pass the arguments in order they are defined in constructor.
Tarea
Extend existing constructor with arguments for university
and gpa
attributes. After that, change the line of object initialization by adding 2 more arguements inside Student()
statement.
¡Gracias por tus comentarios!
Constructor
Constructor is used for object creation and specifying some attributes. Look at this statement:
student = new Student();
Student()
is a constructor of class Student
, so the student
variable is now a Student
object.
This simple constructor is using by default and creates an object only. But you can define a constructor that will initialize some object attributes.
student = new Student('Robert', 22);
student
object now has name Robert and age 22.
The syntax of the constructor inside the class is following:
class Student{ name; university; age; gpa; constructor(name, age){ this.name = name; this.age = age; console.log('Student created'); } sleep(){ console.log('I am sleeping right now!'); } happyBirthday(){ this.age += 1; console.log('Today is my birthday'); } } student = new Student('Robert', 22);
By object creating, you can pass some arguments and use them inside constructor. But note that skipped parameters will have undefined
value. Look at the example and run it to see what happens.
class Student{ name; age; gpa; constructor(name, age, gpa){ // constructor with 3 parameters this.name = name; this.age = age; this.gpa = gpa; console.log('Student created'); } } student = new Student('Robert', 22); // pass only 2 values console.log(JSON.stringify(student)); // object has only 2 defined properties name and age
Only name
and age
properties are defined in student
object because of 2 arguments while student
initialization.
Pass the arguments in order they are defined in constructor.
Tarea
Extend existing constructor with arguments for university
and gpa
attributes. After that, change the line of object initialization by adding 2 more arguements inside Student()
statement.
¡Gracias por tus comentarios!
Constructor is used for object creation and specifying some attributes. Look at this statement:
student = new Student();
Student()
is a constructor of class Student
, so the student
variable is now a Student
object.
This simple constructor is using by default and creates an object only. But you can define a constructor that will initialize some object attributes.
student = new Student('Robert', 22);
student
object now has name Robert and age 22.
The syntax of the constructor inside the class is following:
class Student{ name; university; age; gpa; constructor(name, age){ this.name = name; this.age = age; console.log('Student created'); } sleep(){ console.log('I am sleeping right now!'); } happyBirthday(){ this.age += 1; console.log('Today is my birthday'); } } student = new Student('Robert', 22);
By object creating, you can pass some arguments and use them inside constructor. But note that skipped parameters will have undefined
value. Look at the example and run it to see what happens.
class Student{ name; age; gpa; constructor(name, age, gpa){ // constructor with 3 parameters this.name = name; this.age = age; this.gpa = gpa; console.log('Student created'); } } student = new Student('Robert', 22); // pass only 2 values console.log(JSON.stringify(student)); // object has only 2 defined properties name and age
Only name
and age
properties are defined in student
object because of 2 arguments while student
initialization.
Pass the arguments in order they are defined in constructor.
Tarea
Extend existing constructor with arguments for university
and gpa
attributes. After that, change the line of object initialization by adding 2 more arguements inside Student()
statement.