Benchmark: undefined vs typeof vs in vs hasOwnProperty

Script Preparation code:

var obj = { a: 1, b: 2, c: 3, d: 4, e: 5 };
var keys = new Array(4096 * 5);
for (let i = 0; i < keys.length; i += 1)
  keys[i] = Math.random().toString();

Tests:

undefined
for (let i = 0; i < 4096; i += 1) obj[keys[4096 * 0 + i]] === undefined;
typeof
for (let i = 0; i < 4096; i += 1) typeof obj[keys[4096 * 1 + i]] === "undefined";
in
for (let i = 0; i < 4096; i += 1) keys[4096 * 2 + i] in obj;
hasOwnProperty
for (let i = 0; i < 4096; i += 1) obj.hasOwnProperty(keys[4096 * 3 + i]);
bool
for (let i = 0; i < 4096; i += 1) !obj[keys[4096 * 4 + i]];

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
undefined
typeof
in
hasOwnProperty
bool

Fastest: N/A

Slowest: N/A

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Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/92.0.4495.0 Safari/537.36

Browser/OS: Chrome 92 on Windows

View result in a separate tab

Test name	Executions per second
undefined	1045.1 Ops/sec
typeof	1458.2 Ops/sec
in	2764.5 Ops/sec
hasOwnProperty	1736.8 Ops/sec
bool	1442.7 Ops/sec

undefined vs typeof vs in vs hasOwnProperty (version: 0)

Object lookup performance

Comparing performance of: undefined vs typeof vs in vs hasOwnProperty vs bool

Created: 2 years ago by: Guest

Jump to the latest result

undefined

typeof

in

hasOwnProperty

bool

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A