Run results for: Testing for false vs === undefined vs hasOwnProperty vs in for undefined member

Run details:

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/109.0.0.0 Safari/537.36 Edg/109.0.1518.61

Browser: Chrome 109

Operating system: Linux

Device Platform: Desktop

Date tested: one year ago

Tests:

test truth
var n = {}; while(true) { if(!n.foo) break; }
test undefined
var n = {}; while(true) { if(n.foo===undefined) break; }
test hasOwnProperty
var n = {}; while(true) { if(!n.hasOwnProperty('foo')) break; }
test in ===
var n = {}; while(true) { if('foo' in n === false) break; }
test in !
var n = {}; while(true) { if(!('foo' in n)) break; }