Run results for: undefined

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:73.0) Gecko/20100101 Firefox/73.0

Browser: Firefox 73

Operating system: Windows

Device Platform: Desktop

Date tested: 4 years ago

Test name	Executions per second
undefined w/ type	311472320.0 Ops/sec
undefined w/o type without type check	312447520.0 Ops/sec
typeof equal to	315477760.0 Ops/sec
typeof equal to without type check	311317216.0 Ops/sec
with brackets around typeof unequal	311994400.0 Ops/sec
with brackets around typeof equal	311503040.0 Ops/sec
with brackets around typeof unequal with type check	310524928.0 Ops/sec
with brackets around typeof equal with type check	310987360.0 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'