JSFiddle - React, Tailwind, and code Playground

JavaScript

function return_value(x){return x += 100;}

var delay = function(ms, x){ //x as second parameter for delay-functon
	var promise = new Promise(
  	function(resolve, reject){
  		setTimeout(
      	function(x){
        	resolve("Finished! Return the value: x = "+(return_value(x)));
        	reject("Oww...");
       	}, ms,
        x //x as third parameter for setTimeout
      );
 	 	},
    x //x as second parameter for Promise
	);
  return promise;
}

var f = function(){
  console.log("Start...");
  var x = 100;
  var status = delay(1000, x).then(function(status){console.log("Finish!", status);});
}
f();