JSFiddle - React, Tailwind, and code Playground

HTML

<div>Result:</div>

CSS

div:first-child {
  font-size: 20px;
  font-weight: bold;
  text-decoration: underline;
}

JavaScript

var start = Date.now();
  var iterations = 100000;
  var i, startTime, endTime;
  var x = [[1, 2, 3],[4, 5, 6],[7, 8, 9]];
  var min,max;
  
   startTime = Date.now();
   for (i = 0; i < iterations; i++) {
    x.forEach(function(itm) {
    itm.forEach(function(itmInner) {
      min = (min == undefined || itmInner<min) ? itmInner : min;
      max = (max == undefined || itmInner>max) ? itmInner : max;
     });
    });
   }
   console.log(max,min); // 9, 1
   endTime = Date.now();
   document.body.insertAdjacentHTML('beforeend', "<div>'Normal iteration' took " + (endTime - startTime) + " Milli seconds to execute</div>");
 
 
 
  startTime = Date.now();
  for (i = 0; i < iterations; i++) {
    arr = [[1,2,3],[4,5,6],[7,8,9]].reduce(function (p, c) { return p.concat(c);});
    max = Math.max.apply(null, arr); // 9
    min = Math.min.apply(null, arr); // 1
  }
  console.log(max,min); // 9, 1
  endTime = Date.now();
  document.body.insertAdjacentHTML('beforeend', "<div>'Modern reduce' took " + (endTime - startTime) + " Milli seconds to execute</div>");