My question, how to get count1, count2, .... with below program?

Question

function test(){
var i = i+1;
console.log(isNaN(i));
console.log('count'+i);
}
setInterval(test, 1000);

Output as below-
true
countNaN

Answer 1

Actually the problem is var i=i+1;
In this statement you're trying to initialize i with i variable. How could you use before it gets created. Rewrite it as

var i=0;
function test ()
{
document.write(++i);
or
i=i+1;
document.write(i);
}

hope you understand this

Answer 2

If we initialize variable as number like "var i = 0" inside function, we are getting as NaN only.
but, your solution is working fine,
thanks :)