Run results for: HasOwnProperty + throw or ignore

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:58.0) Gecko/20100101 Firefox/58.0

Browser: Firefox 58

Operating system: Mac OS X 10.13

Device Platform: Other

Date tested: 2025 years ago

Test name	Executions per second
with check	2425.4 Ops/sec
without check	1458.0 Ops/sec

Script Preparation code:

var data = {};
  var max = 1000;
  
  for (let i = 0; i < max; i++) {
    if (Math.random() < 0.85) {
       data[i] = {some: 'value'};
    }
  }

Tests:

with check
for (var i = 0; i < max; i++) { try { setData(i); } catch (e) {} } function setData(i) { if (!data.hasOwnProperty(i)) { throw new Error('data not found'); } var b = data[i].some; }
without check
for (var i = 0; i < max; i++) { try { setData(i); } catch (e) {} } function setData(i) { var b = data[i].some; }

Run results for: HasOwnProperty + throw or ignore

with check

without check