How to Find the Min/Max Elements in an Array in JavaScript

There are multiple methods to find the smallest and largest numbers in a JavaScript array, and the performance of these methods varies based on the number of elements in the array. Let’s discuss each of them separately and give the testing results in the end.

Math.max()

For regular arrays you can use the Math.max with three dots:

Javascript Math.max find max in array

let max = Math.max(...arrayOfNumbers);

Example:

Javascript Math.max find max in array

Using the three dots <kbd class="highlighted">(…)</kbd> makes it easy to call any function expecting arguments.

apply()

The <kbd class="highlighted">Math.max</kbd> function uses the <kbd class="highlighted">apply()</kbd> method to find the maximum element in a numeric array:

Javascript Math.max find max in array

Math.min.apply(Math, testArr);
Math.max.apply(Math, testArr);

Example:

Javascript Math.max.apply find max element in array

The spread operator

The spread operator is also used to get the maximum of an array. It expands an array of numbers into the list of arguments, such as with <kbd class="highlighted">Math.min()</kbd> and <kbd class="highlighted">Math.max()</kbd> :

Javascript Math.max.apply find max element in array

Math.min(...testArr);
Math.max(...testArr);

Math.min.apply(Math, testArr);
Math.max.apply(Math, testArr);

The standard loop

You can use the standard loop for tons of arguments as for loop doesn’t have size limitation:

Javascript the standard loop

let max = testArray[0];
for (let i = 1; i < testArrayLength; ++i) {
  if (testArray[i] > max) {
    max = testArray[i];
  }
}

let min = testArray[0];
for (let i = 1; i < testArrayLength; ++i) {
  if (testArray[i] < min) {
    min = testArray[i];
  }
}

Example:

Javascript the standard loop find max element in array

reduce()

You can also use the <kbd class="highlighted">reduce()</kbd> method for getting the number of items:

Javascript reduce() method for get the max ar min number of items

testArr.reduce(function (a, b) {
  return Math.max(a, b);
});
testArr.reduce(function (a, b) {
  return Math.min(a, b);
});

Example:

Javascript reduce() method for get the max ar min number of items

Maximum Size of the Array

The apply and spread methods had a limitation of 65536 which came from the limit of the maximum number of arguments. In 2019, the limit is the maximum size of the call stack, meaning that the maximum size for the numbers in case of apply and spread solutions is approximately 120000. The following script will calculate the limit for your particular environment:

Javascript maximum size of the array

let testArr = Array.from({
  length: 10000
}, () => Math.floor(Math.random() * 2000000));
for (i = 10000; i < 1000000; ++i) {
  testArr.push(Math.floor(Math.random() * 2000000));
  try {
    Math.max.apply(null, testArr);
  } catch (e) {
    console.log(i);
    break;
  }
}

When you test all the given examples above, the results show that the standard loop is the fastest. Then come the apply and spread methods, after them comes the reduce, which is the slowest one. When dealing with large arrays of more than 40 elements, the spread operator is considered a worse choice compared to other methods.