Let vs Var

HTML

<body>
  Start:<br>
</body>

JavaScript

var body = $("body")

body.append("VAR:<br>");  
for (var i=0;i<10;i++) {
  (function(e){
     setTimeout(function(){
  	   body.append(e +"<br>");  
     },Math.random()*1000);
  })(i);
}

//make lets come after var
setTimeout(function(){

body.append("LET:<br>");  
for (let i=0;i<10;i++) {
	setTimeout(function(){
  	body.append(i +"<br>");  
  },Math.random()*1000);
}
},2000);