JavaScript Dynamic Variable Names

You can only do that with bracket notation, which means you have to attach the variables to something.
The global scope would be window, so that would be window['hello' + newCount], but polluting the global namespace with a bunch of random properties doesn't sound like a good idea, so using an object seems better

var vars = {};
var newCount = parseInt($('#hello').html(), 10);

$('.hello').click(function(){
    newCount++;
    vars['hello' + newCount] = '<p>Hello World</p>';
}); 

alert( vars['hello1'] );

FIDDLE

In JavaScript (as i know) there are 2 ways by which you can create dynamic variables:

eval Function
window object
eval:

var pageNumber = 1;
eval("var text" + pageNumber + "=123;");
alert(text1);
window object:

var pageNumber = 1;
window["text" + pageNumber] = 123;
alert(window["text" + pageNumber]);

for more inforamtion How do i declare and use dynamic variables in javascript?

you can use window

var window['hello' + newCount ] = '<p>Hello World</p>';

likewise..

newCount = document.getElementById('hello').innerHTML;
    $('.hello').click(function(){
        //set count fast enumeration
        newCount++;
        var window['hello' + newCount ] = '<p>Hello World</p>';
        alert(window['hello' + newCount ]);
    }); 

I would just use a simple array to store the variables. Then the object with index n would be variable n etc..

Most simple way

var types = {};

for(var i=1; i<=3; i++){
types["ashish"+i] = 'The value of dynamic variable, val';
}

console.log(types);

you can test it on

jsfiddle