Run results for: String slice vs. array sliceee

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 16_4 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) CriOS/113.0.5672.121 Mobile/15E148 Safari/604.1

Browser: Chrome Mobile iOS 113

Operating system: iOS 16.4

Device Platform: Mobile

Date tested: one year ago

Test name	Executions per second
String concat	63.3 Ops/sec
Array spread	5.8 Ops/sec
Array with concat	5.7 Ops/sec

Tests:

String concat
var arr = new Map() let prev="" for (let i = 0;i<1000;++i){ prev+="ABC:"; arr.set(+i,prev); } function process(s){ return s.slice(0,s.lastIndexOf(':')) } for (const [key,value] of arr){ let s = process(arr.get(key)) while(s.length){ s = process(s) } arr.delete(key) }
Array spread
var arr = new Map() let prev=[] for (let i = 0;i<1000;++i){ prev =[...prev, 'ABC'] arr.set(+i,prev); } function process(s){ return s.slice(0,s.length-1) } for (const [key,value] of arr){ let s = process(arr.get(key)) while(s.length){ s = process(s) } arr.delete(key) }
Array with concat
var arr = new Map() let prev=[] for (let i = 0;i<1000;++i){ prev = prev.concat('ABC') arr.set(+i,prev); } function process(s){ return s.slice(0,s.length-1) } for (const [key,value] of arr){ let s = process(arr.get(key)) while(s.length){ s = process(s) } arr.delete(key) }

Run results for: String slice vs. array sliceee

String concat

Array spread

Array with concat