max value in array javascript

var arr = [1, 2, 3];
var max = arr.reduce(function(a, b) {
  return Math.max(a, b);
});

var numbers = [1, 2, 3, 4];
Math.max(...numbers) // 4
Math.min(...numbers) // 1

x = findMax(1, 123, 500, 115, 44, 88);

function findMax() {
  var i;
  var max = -Infinity;
  for (i = 0; i < arguments.length; i++) {
    if (arguments[i] > max) {
      max = arguments[i];
    }
  }
  return max;
}