Math.max()

The Math.max() function returns the largest of the zero or more numbers given as input parameters, or NaN if any parameter isn't a number and can't be converted into one.

Math.max([value1[, value2[, ...]]])

value1, value2, ...

Zero or more numbers among which the largest value will be selected and returned.

The smallest of the given numbers. If any one or more of the parameters cannot be converted into a number, NaN is returned. The result is -Infinity if no parameters are provided.

Because max() is a static method of Math, you always use it as Math.max(), rather than as a method of a Math object you created (Math is not a constructor).

If no arguments are given, the result is -Infinity.

If at least one of arguments cannot be converted to a number, the result is NaN.

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

Array.reduce() can be used to find the maximum element in a numeric array, by comparing each value:

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

The following function uses Function.prototype.apply() to get the maximum of an array. getMaxOfArray([1, 2, 3]) is equivalent to Math.max(1, 2, 3), but you can use getMaxOfArray() on programmatically constructed arrays. This should only be used for arrays with relatively few elements.

function getMaxOfArray(numArray) {
  return Math.max.apply(null, numArray);
}

The new spread operator is a shorter way of writing the apply solution to get the maximum of an array:

var arr = [1, 2, 3];
var max = Math.max(...arr);

However, both spread (...) and apply will either fail or return the wrong result if the array has too many elements, because they try to pass the array elements as function parameters. See Using apply and built-in functions for more details. The reduce solution does not have this problem.

• Math.min()