Run results for: undefined

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/103.0.0.0 Safari/537.36

Browser: Chrome 103

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 2 years ago

Test name	Executions per second
undefined w/ type	18374640.0 Ops/sec
undefined w/o type without type check	18311990.0 Ops/sec
typeof equal to	18603890.0 Ops/sec
typeof equal to without type check	18557950.0 Ops/sec
with brackets around typeof unequal	18448910.0 Ops/sec
with brackets around typeof equal	18312630.0 Ops/sec
with brackets around typeof unequal with type check	18410300.0 Ops/sec
with brackets around typeof equal with type check	18432030.0 Ops/sec

Script Preparation code:

var obj = {};

Tests:

undefined w/ type
'undefined' !== typeof obj.d;
undefined w/o type without type check
'undefined' != typeof obj.d;
typeof equal to
typeof(obj.d) == 'undefined'
typeof equal to without type check
typeof(obj.d) === 'undefined'
with brackets around typeof unequal
typeof(obj.d) != 'undefined'
with brackets around typeof equal
typeof(obj.d) == 'undefined'
with brackets around typeof unequal with type check
typeof(obj.d) !== 'undefined'
with brackets around typeof equal with type check
typeof(obj.d) === 'undefined'