Run results for: Default parameter vs Empty parameter

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:50.0) Gecko/20100101 Firefox/50.0

Browser: Firefox 50

Operating system: Windows

Device Platform: Other

Date tested: 7 years ago

Test name	Executions per second
Default parameter	415677856.0 Ops/sec
Empty parameter	297326144.0 Ops/sec

Script Preparation code:

function foo(arg = false) {
  return (!arg);
}

function bar(arg) {
  return (!arg);
}

Tests: