Run results for: split...reduce vs Object.assign(split...map)

Run details:

User agent: Mozilla/5.0 (Linux; Android 7.0; LG-M400) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.101 Mobile Safari/537.36

Browser: Chrome Mobile 87

Operating system: Android 7.0

Device Platform: Mobile

Date tested: 3 years ago

Test name	Executions per second
split...reduce	3.4 Ops/sec
split...map	2.8 Ops/sec

Script Preparation code:

var classArray = [];
for (var i=0; i < 100000; i++) {
  classArray.push('class-name');
}
var classes = classArray.join(' ' );

Tests:

split...reduce
classes.split(' ').reduce((acc, item)=>{ return { ...acc, [item]: true, }; }, {});
split...map
Object.assign(classes.split(' ').map(item=> ({[item]: true})));