Run results for: Hash vs insert checks

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.212 Safari/537.36

Browser: Chrome 90

Operating system: Windows

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
includes check on missing value	713728.6 Ops/sec
includes check on existing value	9077614.0 Ops/sec
hash set an existing value	9539889.0 Ops/sec
hash set a missing value	11058759.0 Ops/sec
hash check for missing value then set	12651517.0 Ops/sec
hash check for existing value	11354345.0 Ops/sec

Script Preparation code:

var arr = [];
var hash = {};

for(var i=0; i < 1000; i++){
  arr.push(i.toString());
  hash[i.toString()] = { val : i.toString() }
}

Tests:

includes check on missing value
if (!arr.includes('missing')){ arr.push('missing'); arr.push('another'); }
includes check on existing value
if (!arr.includes('1')){ arr.push('missing'); arr.push('another'); }
hash set an existing value
hash['1'] = {val : '1'};
hash set a missing value
hash['missing'] = {val : 'missing'};
hash check for missing value then set
if (!hash['missing']) { hash['missing'] = {val : 'missing'}; }
hash check for existing value
if (!hash['1']) { hash['1'] = {val : '1'}; }