JavaScript - Math.max() method example

The Math.max() function returns the highest number from given numbers.

// ONLINE-RUNNER:browser;

var max = Math.max(2, 5);
console.log( max ); // 5

console.log( Math.max(1) ); // 1
console.log( Math.max(1, 2) ); // 2
console.log( Math.max(1, 2, 3) ); // 3
console.log( Math.max(3, 25, -6, 0) ); // 25

console.log( Math.max(-5, -2, -7) ); // -2
console.log( Math.max(2, 1, NaN) ); // NaN
console.log( Math.max() ); // -Infinity

Math.max() function usage with an array in ES5 and ES6 example:

// ONLINE-RUNNER:browser;

var array = [10, 5, 0];

// In ES5
console.log( Math.max.apply(Math, array) ); // 10

// In ES6 - Spread Operator (...) has been introduced 
console.log( Math.max(...array) ); // 10
console.log( Math.max(100, ...array, 120, ...[151, 152]) ); // 152

1. Documentation

2. Getting max value from array examples

2.1. With Array reduce method example

This approach uses reduce method to find the maximum value inside the array. By making small modifications of Math.max(a, b) instruction we are able to find maximal value inside properties of a and b variables.

// ONLINE-RUNNER:browser;

var array = [1, 2, 3];

var result = array.reduce(function(a, b) {
    return Math.max(a, b);
});

console.log(result); // 3

2.2. Recurrent max method example

This approach uses recurrence to find the maximum value inside an array of nested arrays.

// ONLINE-RUNNER:browser;

function findMax() {
  function checkEntry(entry) {
    if (entry instanceof Array) {
        return findMax.apply(null, entry);
      }
      
      return entry;
  }

  if (arguments.length > 0) {
    var result = checkEntry(arguments[0]);

    for (var i = 1; i < arguments.length; ++i) {
      var value = checkEntry(arguments[i]);

      if (value > result) {
        result = value;
      }
    }

    return result;
  }

  return NaN;
}

console.log(findMax(1, 2, 3, [4, 5, 6],[7, 8, [9, 10]])); // 10

References

1. Maxima and minima - Wikipedia