Classes


var myObject = { 
   property1 : MyProp,
   method1 : function() {
   }
   property2_Array : [ {arrayelement1 : "one"} {arrayelement2 : "two"} ];
}

A empty object literal

var myObject = { } 

This uses object literal notation

var myobject = { 
   name: "MyName",
   age: 20
};



Object Literals

This has 2 members
One property and one method

var myObject = { 
   Property_Status : "Ready",
   Method_DoSomething : function() {
      alert('something');
   }
}


Declaring

Classes are just special types of functions with additional functionality.
There are two ways you can define a class.
You can either use a declaration or an expression.



Class Declaration

Class declarations are not hoisted (like function declarations)
You always need to declare your class before you use it.


List Of Objects

var list = [ 
   { name: 'David', id: 42 },
   { name: 'Steven', id: 65 }
];


Class Expression

These can be named or unnamed


let Something = class Something { 
   constructor(myheight, mywidth) {
      this.height = myheight;
      this.width = mywidth;
   }
};
console.log(Something.name);

Constructor

This is a special method used for creating and initializing the object.
A constructor can use the "super" keyword to call the constructor of the super class.



this

You can use 'this' keyword to refer to the current object.
this' refers to the calling object in a method


function validate(obj, lower, upper) { 
   if ( (obj.value < lower) || (obj.value > upper) ) {
      alert('out of range');
   }
}

<input type="text" name="age" size="3"
    onChange="validate(this, 18, 99)">


© 2019 Better Solutions Limited. All Rights Reserved. © 2019 Better Solutions Limited TopNext