Run results for: set.has vs. array.includes vs in operator (with strings)

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/119.0.0.0 Safari/537.36

Browser: Chrome 119

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
includes	23036430.0 Ops/sec
lookup	23468558.0 Ops/sec
in	23270338.0 Ops/sec

Script Preparation code:

var a = [];
for (let i = 0; i < 100_000; i++) {
  a.push(i.toString());
}
var b = new Set(a)
var c = {}
for (const key of a) {
  c[key] = 0; 
}

Tests:

includes
return a.includes("9")
lookup
return b.has("9")
in
return "9" in c

Run results for: set.has vs. array.includes vs in operator (with strings)

includes

lookup

in