What is the output of the following? “`js const target = { a: 1 }; const handler = { set(obj, prop, value) { obj[prop] = value * 2; return true; } }; const p = new Proxy(target, handler); p.b = 5; console.log(target.b); “` JavaScript DeveloperHard Try Now
What is the output of the following? “`js function Person(name) { this.name = name; } Person.prototype.greet = function() { return `Hi, ${this.name}`; }; const p = Object.create(Person.prototype); p.name = ‘Alice’; console.log(p.greet()); console.log(p instanceof Person); “` JavaScript DeveloperHard Try Now
What is the correct way to handle multiple async operations where you want ALL results including failures? JavaScript DeveloperHard Try Now
What is memoization and how would you implement it for a pure function in JavaScript? JavaScript DeveloperHard Try Now
What is the output of the following? “`js const map = new Map(); const key = {}; map.set(key, ‘value’); console.log(map.get({})); console.log(map.get(key)); “` JavaScript DeveloperHard Try Now
What is the output of the following? “`js let result = []; for (var i = 0; i < 3; i++) { result.push(() => i); } console.log(result.map(fn => fn())); “` JavaScript DeveloperHard Try Now
What is the difference between `Object.getPrototypeOf(obj)` and `obj.__proto__`? JavaScript DeveloperHard Try Now
What is the output of the following? “`js async function* asyncGen() { yield 1; yield 2; } async function run() { const gen = asyncGen(); console.log((await gen.next()).value); console.log((await gen.next()).value); } run(); “` JavaScript DeveloperHard Try Now
What is module scope in ES modules and how does `import` differ from CommonJS `require()`? JavaScript DeveloperHard Try Now
What is the output of the following? “`js const obj = { value: 42, getValue: function() { return this.value; }, getValueArrow: () => this.value }; console.log(obj.getValue()); console.log(obj.getValueArrow()); “` JavaScript DeveloperHard Try Now
What is the output of the following? “`js class Animal { constructor(name) { this.name = name; } speak() { return `${this.name} makes a noise.`; } } class Dog extends Animal { speak() { return `${this.name} barks.`; } } const d = new Dog(‘Rex’); console.log(d.speak()); console.log(d instanceof Animal); “` JavaScript DeveloperHard Try Now
What is tail call optimization and which JavaScript syntax enables it in strict mode? JavaScript DeveloperHard Try Now
What is the output of the following? “`js const handler = { get(target, key) { return key in target ? target[key] : 37; } }; const p = new Proxy({a: 1}, handler); console.log(p.a, p.b); “` JavaScript DeveloperHard Try Now
What is the output of the following? “`js console.log(1 + ‘2’ + 3); console.log(1 + 2 + ‘3’); “` JavaScript DeveloperHard Try Now
What is the correct way to implement a custom iterable in JavaScript? JavaScript DeveloperHard Try Now
