maximum number after this number in the array code example

Example 1: Find the maximum number of an array js

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

Example 2: Find the maximum number of an array js

Math.max(10, 20);   //  20
Math.max(-10, -20); // -10
Math.max(-10, 20);  //  20