class - Instance Variables in Javascript Classes -

i code in php , java, work on front end of project , use javascript. create objects differently below, came across , caught interest being syntax similar program in.

i poking around, trying figure out how use instance variables in javascript classes using syntax below. i've tried declaring instance variables name;, or _name;, or var name;, or of previous variables , adding = null;, still errors in console. errors my-file.js:2 uncaught syntaxerror: unexpected identifier. i'm trying set instance variable through constructor.

how use instance variables in javascript, using syntax below?

class myclass {   var _name;    constructor(name) {     _name = name;     alert("hello world, oo js!");     this.myfunction();   }    myfunction() {     document.getelementbyid("myelement").addeventlistener("click", function() {         console.log("ant's function runs. hello!");     });   } }  window.onload = function() {   var person = "john smith";   var myclass = new myclass(person); } 

this still proposal , follows:

class {    property = "value"; } 

btw, when want access class property (i.e. own object property) you'll still need use this.property:

class {     property = "value";      constructor() {         console.log(this.property);     } } 

if want use syntax today, you'll need use transpiler babel.