Run results for: try/catch vs check

Run details:

User agent: Mozilla/5.0 (X11; Fedora; Linux x86_64; rv:50.0) Gecko/20100101 Firefox/50.0

Browser: Firefox 50

Operating system: Fedora

Device Platform: Other

Date tested: 7 years ago

Test name	Executions per second
try	13822.6 Ops/sec
check	21487.1 Ops/sec
try (bad)	145.4 Ops/sec
check (bad)	4618.3 Ops/sec

Script Preparation code:

function log() {
  var str = "";
  for (var i = 0; i < arguments.length; ++i) {
    str += String(arguments[i]);
  }
}

var resA;
function doTry (e) {
  try {
    resA = e.details[0];
  } catch (err) {
    log("unexpected format of event:", err.toString());
  }
}

var resB;
function doCheck (e) {
  if (e && e.details) {
    resB = e.details[0];
  } else {
    log("unexpected format of event:", e);
  }
}

var goodEvents = [];
for (var i = 0; i < 10000; ++i) {
  goodEvents.push({ details: [ Math.random() ] });
}

var badEvents = [];
for (var i = 0; i < 10000; ++i) {
  if (i % 20 === 0) {
    badEvents.push(null);
  } else if (i % 20 === 10) {
    badEvents.push({});
  } else {
  	badEvents.push({ details: [ Math.random() ] });
  }
}

function test (events, fn) {
  for (var i = 0; i < events.length; ++i) {
    fn(events[i]);
  }
}

Tests:

try
test(goodEvents, doTry);
check
test(goodEvents, doCheck);
try (bad)
test(badEvents, doTry);
check (bad)
test(badEvents, doCheck);

Run results for: try/catch vs check

try

check

try (bad)

check (bad)