Run results for: JSON with and without filter

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 9_3_5 like Mac OS X) AppleWebKit/601.1.46 (KHTML, like Gecko) Version/9.0 Mobile/13G36 Safari/601.1

Browser: Mobile Safari 9

Operating system: iOS 9.3.5

Device Platform: iPhone

Date tested: 8 years ago

Test name	Executions per second
Plain JSON stringify	1503.6 Ops/sec
With filter	675.8 Ops/sec

Script Preparation code:

var bigdata = {};
for (var i = 0; i < 100; i++) {
  var usdata = {
    name: 'user' + i,
    surname: 'user' + i,
    friends: {}
  };

  for (var j = 0; j < 10; j++) {
    usdata.friends['friend' + j] = {
      _ref: 'firend' + j
    };
  }

  bigdata['user' + i] = usdata;
}

Tests:

Plain JSON stringify
var str = JSON.stringify(bigdata);
With filter
var str = JSON.stringify(bigdata, function(k,v) { return (k.charAt(0) == '$') ? undefined : v; });

Run results for: JSON with and without filter

Plain JSON stringify

With filter