Run results for: Can add to WeakSet ?

Run details:

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/61.0.3163.79 Safari/537.36

Browser: Chrome 61

Operating system: Linux

Device Platform: Other

Date tested: 7 years ago

Test name	Executions per second
Switch-Case 2	15.1 Ops/sec
!== null && (typeof \|\| typeof)	22.6 Ops/sec

Script Preparation code:

var DATA = (function (K, N, total) {
    function random(n) {
        return Math.floor(Math.random() * 7);
    }

    function randomKey() {
        return Math.random().toString(36).slice(2);
    }

    function randomCollection(count = random(N)) {
        for (var a = new Array(count), i = 0; i < count; i++) {
            a[i] = randomValue();
        }

        return a;
    }

    function randomObject(keysCount = random(N)) {
        for (var obj = {}, i = 0; i < keysCount; i++) {
            obj[randomKey()] = randomValue();
        }

        return obj;
    }

    function randomValue(type = random(K)) {
      switch (type % K) {
        case 0: return undefined;
        case 1: return null; break;
        case 2: return String(Math.random());
        case 3: return Math.random() > 0.5;
        case 4: return Math.random() * 1E3;
        case 5: return randomCollection();
        default: return randomObject();
      }
    }

    return randomCollection(total);
}(7, 5, 1E6));


function canBeAddedToWeakSet_switch2(value) {
  switch (typeof value) {
    case 'undefined':
      return String(value) === '[object HTMLAllCollection]'
    case 'boolean':
    case 'number':
    case 'string':
    case 'symbol':
      return false
    case 'object':
      return value !== null
    default:
      return true
  }
}

function canBeAddedToWeakSet_null_typeof_x2(value) {
    return value !== null && (typeof value === 'object' || typeof value === 'function');
}

function test(canAdd) {
    const count = DATA.reduce((countOfAddables, value) => (canAdd(value) ? 1 : 0) + countOfAddables, 0);
  	console.log('can add %d out of %d values in the array', count, DATA.length);
}

Tests:

Switch-Case 2
test(canBeAddedToWeakSet_switch2);
!== null && (typeof || typeof)
test(canBeAddedToWeakSet_null_typeof_x2);

Run results for: Can add to WeakSet ?

How to check beforehand that the value won't throw exception when added to WeakSet in JavaScript? What is the most performant way?

Switch-Case 2

!== null && (typeof || typeof)