javascript - Fetching an ID on onclick of a button -

i trying create button dynamically inside loop. onclick of button want fetch id of button. below code not working. can please me.

 for(int i=1;i<5;i++)     {     var btn = document.createelement("button");     btn.innertext = "button"+i;     btn.setattribute("id", i);     btn.onclick = function(this){     alert(this.id);     }     } 

thanks in advance

you had append child . , cannot use int here . use var

for(var i=1;i<5;i++)      {      var btn = document.createelement("button");            btn.innertext = ("button"+i);      btn.setattribute("id", i);        document.body.appendchild(btn); // add line       btn.onclick = function(){      alert(this.id);      }    }