Objects Flashcards
What are objects?
- collection of variables and functions
- they represent the attributes and behaviour of something used in a program
What are variable tied to object called?
Properties
What are function tied to object called?
Methods
Properties and methods are also called?
Properties = attributes
Methods = behaviors
What is dot notation used for? (.currentTime)
It can be used to add a property or add a method and can also be used to consume
What is the literal notation to create an object?
E.g
let nameOfTheObject = {}
How do you add property to an object?
objectName.property = ‘something’
How do you add a method to an object?
objectName.functionName = function(){
//cool stuff
}How do you change the value of an object property?
Whit this syntax:
myObject.myProperty = newValue
How can a constructor be differentiate from a function?
The name in the function is capitalized
What is a constructor?
A constructor is a function that has as a purpose to create objects
Create an object ‘mouse’ and give it 3 property and 1 methods
let mouse = {}
mouse. brand = ‘logitech’
mouse. color = ‘black’
mouse. wireless = ‘true’
mouse.leftClick = function() {
consol.log(‘LEFT CLICKKKK’)
}
What does the key word ‘this’ indicate?
‘This’ is used in constructor to replace the name of the object
What is the syntax of a constructor?
function. NameOfConstructor (brand,model,color){
this. brand = …
this. model = …
this. color = …
this.something = function{
alert(…)
}
}
When a function name starts with a capital letter what does that mean?
It means it is a constructor
What is the syntax to create a new object using a constructor?
let nameOfNewObject = new NameOfConstructor (‘different values’, ‘…’, ‘…’, ‘…’)
What is a prototype?
It is a fall-back source of property and methods.
What happens if an object does not have a property or method?
If an object does not have a property or value can go up its prototype chain to check for the value until it hits the global object prototype.
What are the 4 pillar of object oriented programming (OOP)?
- Encapsulation
- Inheritance
- Abstraction
- Polymorphism
What is encapsulation in OOP?
Encapsulation refers to the grouping of related variable and function that operates on them into objects
What is abstraction in OOP?
It refers to the possibility of hiding some of the property and methods in order to make the interface of those objects simpler and it also helps to reduce the impact of change.
What is inheritance in OOP?
It helps us to eliminate redundant code that similar element have in common by just defining it once and then have other objects inherit those methods
What is polymorphism in OOP?
with polymorphism we can restructure ugly switch/case statements
