Run results for: slicing regex vs sticky regex

Run details:

User agent: Mozilla/5.0 (X11; Linux x86_64; rv:109.0) Gecko/20100101 Firefox/114.0

Browser: Firefox 114

Operating system: Linux

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
slice then regex	12391.9 Ops/sec
sticky regex	16823.2 Ops/sec

Script Preparation code:

s = ""
for (let i = 0; i < 1500; i++) {
    s += String.fromCharCode((Math.random() * (127 - 30) + 32) | 0)
}
FILTER = /\w/
R1 = /^\w\d/
R2 = /\w\d/y

Tests:

slice then regex
let count = 0 for(let i = 0; i < s.length; i++) { if (FILTER.test(s[i])) { let ss = s.slice(i,i+2) if (R1.test(ss)) { count++ } } }
sticky regex
let count = 0 for(let i = 0; i < s.length; i++) { if (FILTER.test(s[i])) { R2.lastIndex = i let m = R2.exec(s) if (m != null) { count++ } } }

Run results for: slicing regex vs sticky regex

slice then regex

sticky regex