setInterval with a function PARAMETER of global variable not working

setInterval with a function PARAMETER of global variable not working

https://jsfiddle.net/jsfiddle135/xpvt214o/956977/


Symptom: setInterval works fine with a global variable WITHOUT ANY parameter.
                 But with a function parameter, the global variable is not passed as a function 
                 parameter.


-------------------------
$(document).ready(function(){

         var str; str=""; var num;  
  
function display(num){   // NOT WORKING
function display(){   // Fine
    num++;
    str=str+num
$("#textid").text(str);
}

setInterval(display, 1000, num);   // NOT WORKING
setInterval(display, 1000);   // Fine

$("#btn").click(function(){
num = 100;
});


});