+function () {
const boolPrim = Boolean(0); // Wrapping function (WF)
const boolObj = new Boolean(false); // Wrapping object (WO)
// 1. WF returns primitive type while WO reurns reference type
console.log('1. WF:', typeof boolPrim); // "boolean"
console.log('1. WO:', typeof boolObj); // "object"
// 2. WF is friendly with strict equal operator (===), while WO is not.
console.log('2. WF:', boolPrim === false); // true
console.log('2. WO:', boolObj === false); // false
// 3. WF is friendly with "Truthy and Falsy rules" in JS, while WO is not.
// See more: https://www.sitepoint.com/javascript-truthy-falsy/
console.log('3. WF:');
if (boolPrim) {
console.log('I am truthy');
} else {
console.log('I am falsey');
}
console.log('3. WO:');
if (boolObj) {
console.log('I am truthy');
} else {
console.log('I am falsey');
}
// 4. Never use WO. Use WF for better readability
const arr = [];
console.log('4. Truthy WF vs double negativity:', Boolean(arr) === !!arr); // true
console.log('4. Common trick to parse boolean:', !!arr === true); // true
}();
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