Run results for: isIteratorOrAsyncIterator

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_6) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/13.0.5 Safari/605.1.15

Browser: Safari 13

Operating system: Mac OS X 10.14.6

Device Platform: Desktop

Date tested: 4 years ago

Test name	Executions per second
null check with next typeof check	6533637.0 Ops/sec
boolean check with next typeof check	6526039.0 Ops/sec
boolean check with next boolean check	6400166.5 Ops/sec
null or undefined with next typeof check	907124.2 Ops/sec
null or undefined with boolean next check	917572.9 Ops/sec

HTML Preparation code:

var a = (function *() {})();
var b = undefined;
var c = null;
var d = {next: () => ({value: 1, done: false})};

Script Preparation code:

var a = (function *() {})();
var b = undefined;
var c = null;
var d = {next: () => ({value: 1, done: false})};
var values = [a, b, c, d];

Tests:

null check with next typeof check
for (const value of values) { if (value != null && typeof value.next === "function") { } }
boolean check with next typeof check
for (const value of values) { if (value && typeof value.next === "function") { } }
boolean check with next boolean check
for (const value of values) { if (value && value.next) { } }
null or undefined with next typeof check
for (const value of values) { if (value !== undefined && value !== null && typeof value.next === "function") { } }
null or undefined with boolean next check
for (const value of values) { if (value !== undefined && value !== null && value.next) { } }