Run results for: Find Smallest Number Not In An Array

Run details:

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/111.0.0.0 Safari/537.36

Browser: Chrome 111

Operating system: Linux

Device Platform: Desktop

Date tested: 2 years ago

Test name	Executions per second
Set With For Loop	4812.8 Ops/sec
Sort With For Loop	642.0 Ops/sec
Sort With Reduce	329.5 Ops/sec

Script Preparation code:

var array = [];
array.length = 10000;
array.fill(undefined);
array = array.map(() => Math.floor(Math.random() * array.length));

AخA
 
var array = [];array.length = 10000;array.fill(undefined);array = array.map(() => Math.floor(Math.random() * array.length));

Tests:

Set With For Loop

const set = new Set(array);

function findSet() {
  for (let i = 0; i < array.length; i++) 
    if (!set.has(i)) return i;

  return -1;
}

findSet();

​x
 
const set = new Set(array);​function findSet() {  for (let i = 0; i < array.length; i++)     if (!set.has(i)) return i;​  return -1;}​findSet();

Sort With For Loop

const sortedArray = array.slice().sort((a, b) => a - b);

function findSort() {
	for (let i = 0; i < array.length; i++)
      if (!sortedArray.includes(i)) return i;
  
  return -1;
}

findSort();

 
const sortedArray = array.slice().sort((a, b) => a - b);​function findSort() {    for (let i = 0; i < array.length; i++)      if (!sortedArray.includes(i)) return i;    return -1;}​findSort();

Sort With Reduce

const sortedReduceArray = array.slice().sort((a, b) => a - b);

function findReduce() {
	return sortedReduceArray.reduce((acc, current) => (Math.abs(current - acc) > 1 ? Math.min : Math.max)(current, acc), 0) + 1;
}

findReduce();

 
const sortedReduceArray = array.slice().sort((a, b) => a - b);​function findReduce() {    return sortedReduceArray.reduce((acc, current) => (Math.abs(current - acc) > 1 ? Math.min : Math.max)(current, acc), 0) + 1;}​findReduce();