Run results for: Accessing Property of Object Directly vs. Defensively

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/72.0.3626.121 Safari/537.36

Browser: Chrome 72

Operating system: Mac OS X 10.14.3

Device Platform: Desktop

Date tested: 5 years ago

Test name	Executions per second
Direct Access	15984020.0 Ops/sec
Defensive Checks for Existence: Standard	3986630.0 Ops/sec
Defensive Checks for Existence: Using `hasOwnProperty`	1816648.0 Ops/sec

Script Preparation code:

var response = {
  data: {
    property: "value",
  },
};

Tests:

Direct Access
function directAccess () { return response.data.property; } directAccess();
Defensive Check for Existence via If-statement
function defensiveCheckForExistenceViaIfStatement () { if (response && response.data && response.data.property) { return response.data.property; } } defensiveCheckForExistenceViaIfStatement();
Defensive Check for Existence via If-statement using `hasOwnProperty`
function defensiveCheckForExistenceViaIfStatementUsingHasOwnProperty () { if (response && Object.prototype.hasOwnProperty.call(response, 'data') && Object.prototype.hasOwnProperty.call(response.data, 'property') ) { return response.data.property; } } defensiveCheckForExistenceViaIfStatementUsingHasOwnProperty();
Defensive Check for Existence via Chaining
function defensiveCheckForExistenceViaChaining () { return response && response.data && response.data.property; } defensiveCheckForExistenceViaChaining();
Defensive Check for Existence via Chaining using `hasOwnProperty`
function defensiveCheckForExistenceViaChainingUsingHasOwnProperty () { return ( response && Object.prototype.hasOwnProperty.call(response, 'data') && Object.prototype.hasOwnProperty.call(response.data, 'property') ); } defensiveCheckForExistenceViaChainingUsingHasOwnProperty();