Property in TypeScripts

Property can be used to set or get private field of a class

Property declaration requires 2 accessors set and get

Syntax:

  public set <propertyname>(para)
  {
     set private field and perform calculation (or) validation
  }

  public get <propertyname>():<type>
  {
       return private field
  }

  Property is a combination of 2 blocks
 1.set block--writting to a property will execute set block
 2.get block--reading a property will execute get block

Example

   Emp class
     |
   sal property[set{da=sal*0.3} and get{..} blocks]
   _sal private field
   _da  private field

  e=new emp();
  e.sal=10000;-->set block execution[da=3000]

  e.sal=e.sal+5000;
          |
        reading[get block execution]
          |
         10000+5000
             |
          15000
        |
     set block exec[da=4500]

Property looks like normal public field, but internal execution will be like
methods.

Property is recommended when you want to perform calculation validation
based on specific private field.


Example















Note:
Accessors are only available when targeting ECMAScript 5 and higher

Output
empno:1 sal:10000 da:3000
empno:1 sal:15000 da:4500

Note:
*target ECMAScript version can be given to tsc using "target[-t]" option
  syntax:
       tsc <tsfilename> -t ecmascript version[es5|es6|..]


Sample way of calling ECMAScript 
*goto terminal
  >tsc propertydemo.ts -t es5
  >node propertydemo